A study to determine a tentative minimum standard of hearing for efficient stenographers

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A STUDY TO DETERMINE A TENTATIVE MINIMUM STANDARD OF HEARING FOR EFFICIENT STENOGRAPHERS

A T h e s is P r e se n te d to t h e F a c u l t y o f t h e S c h o o l o f E d u c a tio n The U n i v e r s i t y o f S o u t h e r n C a l i f o r n i a

In P a r t ia l F u lfillm e n t o f t h e R e q u ir e m e n ts f o r t h e D eg ree M a ste r o f S c i e n c e i n E d u c a tio n

by C h a r l o t t e J o s e p h i n e W ils o n A u g u st 1 9 4 3

UMI Number: EP56466

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion.

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Set

W7^7

thesis, writ ten under the direction of the Chairman of the candidate’s Gui dan ce C o m m i t t e e an d a p p r o v e d by all me m be rs of the C o m m it te e , has been pr es e nt e d to an d a c ce p te d by the F acu lty of the S c h o o l of E duc at io n of T h e Univ ers ity of Southern California in p a r ti a l fu lfillment of the requirements fo r the degree of M a s t e r of Science in Education.

Date

Ma? . . 2 2 -...1 9 4 3 .....................

Dean Guidance Committee

S. G. Blackstone Chairman

F. J. Weerslng

M. M. Thompson

Aa £ ,

TABLE: OF CONTENTS CHAPTER

PAGES THE PROBLEM AND DEFINITIONS OF TERMS USED The p r o b le m

•

•

•

•

S t a t e m e n t o f th e p r o b le m R e l a t e d p r o b le m s

•

•

S c o p e o f th e s t u d y

*

•

1 -3

•

3 -4

•

5 -1 0 11

I m p o r ta n c e o f th e s t u d y •

•

1 3 -1 5

A n a ly s is o f th e stu d y

*

•

1 3 -1 6

V a l i d a t i o n an d n e e d o f fu r th e r stu d y

• •

•

16

•

1 7 -3 0

L i m i t a t i o n s o f th e s t u d y D e f i n i t i o n s o f te r m s u s e d

T e n t a t i v e .......................................31 Minimum

.o

.

.

S ta n d a r d

•

•

H e a r in g

.......................................31

.

31 31

O t o l o g i s t .......................................31 E f f ic ie n t ste n o g r a p h er O th e r d e f i n i t i o n s

.

.

.

*

31

.

zz

O r g a n iz a t io n o f t h e r e m a in d e r . . . . o f th e t h e s i s

zz

REVIEW OF RELATED LITERATURE 1

T he S t a t u s o f B u s i n e s s E d u c a tio n and J u s t i f i c a t i o n o f t h e P r o b le m 8 3 - 4 1

PAGES

FART

2 3 4

T he P s y c h o lo g y and P h y s i o l o g y o f H e a r in g

4 2 -6 4

T he R e l a t i o n o f S p e e c h and H e a r in g t o S h o r th a n d

6 5 -8 1

M eth o d s o f T e s t i n g H e a r in g

8 2 -8 3

T he V o ic e

8 4 -8 9

The W atch T e s t

89

The A e o u m e ter

90 9 0 -9 1

T u n in g F o r k s G a lt o n W h i s t l e

92

T he Mono c h o r d

92

N y sta g a m u s T e s t

93

The C o n d it io n e d R e f l e x The A u d io m e te r

' 93 9 4 -1 0 7

.

H e a r in g S u r v e y s and S c h o o l T e s t s The U n it e d S t a t e s P u b l i c H e a lt h S e r v ic e Survey .

1 0 8 -1 1 0 1 1 0 -1 1 3

The New Y ork and S an F r a n c i s c o W o rld 1s F a i r s ’ H e a r in g T e s t s l l 3 - 1 1 9 1 2 0 -1 3 3

O th e r S t u d i e s 6 III

•

1 3 4 -1 4 9

SOURCES OF DATA AND METHODS OF PROCEDURE .

1 5 0 -1 6 3

FINDINGS AND CONCLUSIONS

1 6 4 -1 7 7

R e la te d I n v e s t ig a t io n s

BIBLIOGRAPHY

.

.

G L O S S A R Y ..........................................

1 7 8 -1 8 8

CHAPTER I THE PROBLEM AND DEFINITIONS OF .TERMS USED The m o r t a l i t y r a t e o f s t e n o g r a p h i c s t u d e n t s i s v e r y h ig h .

T h is o b s e r v a t i o n h a s b e e n made b y s h o r th a n d t e a c h e r s

and e d u c a t o r s f o r many y e a r s , b u t no one h a s u n d e r ta k e n t o fin d

o u t d e f i n i t e l y w h at p e r c e n t a g e o f s h o r th a n d e n r o l l e e s

a r e e v e n t u a l l y and s u c c e s s f u l l y e m p lo y e d o f t h e num ber who e i t h e r b e g i n o r c o m p le te t h e s t e n o g r a p h ic c o u r s e .

H o w ev er,

som e a t t e m p t s h a v e b e e n m ade. P a u l L . T u r s e , o f P e a k s k i l l , New Y o r k , s t a t e s t h a t " f a r t o o many p u p i l s h a v e b e e n s t u d y i n g s h o r th a n d f o r v o c a ­ t i o n a l u s e . ” -*-

T h i s , o f c o u r s e , r e s u l t s i n tr e m e n d o u s w a s t e

i n t i m e , e n e r g y , m o n ey , and p u p i l d is c o u r a g e m e n t . s e r v a t i o n i s b a s e d on s e v e r a l s t u d i e s .

T h is ob­

Of 7 4 6 p u p i l s i n

t w e l v e d i f f e r e n t h ig h s c h o o l s who b e g a n t h e s t u d y o f s h o r t h a n d , o n l y SB8 s u r v i v e d t h e

c o u r s e w h ic h i n d i c a t e s an e n r o llm e n t

m o r t a l i t y o f 60 p e r c e n t .

I n a n o t h e r s t u d y , a s h o r th a n d s u ­

p e r v i s o r fo u n d t h a t d u r in g a f i v e - y e a r p e r i o d , 7 1 p e r c e n t o f t h o s e b e g i n n in g t h e s t u d y o f s h o r th a n d f a i l e d t o th e tw o -y e a r c o u r s e .

c o m p le te

D r . E lm er E . S p a n a b e l ,o f t h e P i t t s b u r g h

' P a u l L; T u r se , "The S e l e c t i o n o f P u p i l s f o r S t e n o ­ g r a p h ic C o u r s e s , "F o u r t e e n t h Ye a r b o o k , E a s t e r n C o m m ercia l T e a c h e r s * A s s o c i a t i o n ^ ( 1 2 0 0 W alnu t S t r e e t , P h i l a d e l p h i a , 1941) p p . 3 0 3 -3 0 5 .

2

s c h o o l s , fo u n d t h a t o u t o f 5 6 0 p u p i l s e n r o l l e d i n s h o r t h a n d , ;281 o r 50 p e r c e n t d ro p p ed o u t o f t h e c o u r s e a t t h e end o f th e f i r s t year*

On t h e b a s e s o f t h e s e and s i m i l a r s t u d i e s ,

Mr. T u r s e w as c o n v in c e d t h a t t h e m o r t a l i t y r a t e o f s h o r t ­ hand s t u d e n t s w as a s h ig h o r h i g h e r t h a n t h a t o f a n y o t h e r sc h o o l su b je ct as i t

r e q u ir e d th e h ig h e s t ty p e o f p e r s o n a l,

m e n t a l , and m an u al q u a l i t i e s .

**■

R e c e n t l y , t e a c h e r s and e d u c a t o r s who a r e p a r t i c u l a r l y in te r e s te d

in th e tr a in in g o f e f f i c i e n t

d i r e c t e d much t h o u g h t t o t h i s p r o b le m .

ste n o g r a p h e r s, have E x te n s iv e r e se a r c h

h a s b e e n don e a s t o t h e p o s s i b l e c a u s e s f o r t h i s c o n t in u o u s d e c r e a s e o f s t u d e n t s i n t h e m ore a d v a n c e d c o u r s e s o f s h o r t ­ hand a s w e l l a s t o t h e d e c r e a s e o f e m p lo y a b le e f f i c i e n t n o g ra p h ers.

ste > ~

T h e s e i n v e s t i g a t i o n s h a v e b e e n r e l a t e d to many

p h a s e s o f s t e n o g r a p h y , e s p e c ia lls * - t o m e th o d s , s u b j e c t - m a t t e r , m o to r a b i l i t y , t r a n s c r i p t i o n d i f f i c u l t i e s , p e n m a n sh ip , s t a n ­ d a r d s o f p r o d u c t i o n , and o t h e r p h a s e s o f t h e s t u d y . As t h e a b i l i t y t o t a k e d i c t a t i o n b y s h o r t h a n d , s t e n o ty p e ,

o r fr o m r e c o r d i n g s on t h e e d ip h o n e and d ic t a p h o n e i s

e n t i r e l y d e p e n d e n t upon t h e s t e n o g r a p h e r ’ s p ow er t o p e r c e i v e c o m p le x e x p r e s s i o n s o f a r t i c u l a t i o n and t r a n s m i t th em t o t h e b r a i n b y m ean s o f t h e v e r y d e l i c a t e and i n t r i c a t e .m e c h a n i s m

1 I b id , p . 305.

o f h e a r i n g , i t w as c o n s i d e r e d t h a t p o s s i b l y o n e o f t h e f a c ­ t o r s r e s p o n s ib le f o r t h i s h ig h m o r t a lit y r a te o f s te n o g r a p h e r s m ig h t b e due t o c e r t a i n a b n o rm a l c o n d i t i o n s o f t h e . h e a r i n g o rg a n ism * S t a t e m e n t o f t h e p r o b le m . S p e c i f i c a l l y s t a t e d , t h e p r o b le m o f t h i s s t u d y w as t o d e t e r m in e a t e n t a t i v e minimum s t a n d a r d o f h e a r in g f o r e f f i c i e n t

s t e n o g r a p h e r s on t h e b a s i s

o f a s t u d y o f h e a r in g t e s t s g i v e n t o tw o g r o u p s o f s t u d e n t s e n r o l l e d i n t h e f i r s t y e a r s h o r th a n d c l a s s e s .

B e c a u s e o f th e

n a t u r e o f t h e s t u d y , i t w as n e c e s s a r y t o e m p lo y a num ber o f te c h n iq u e s in v o lv e d in th e p r in c ip l e s o f r e se a r c h * The l i b r a r y t e c h n i q u e w as u s e d i n e x a m in in g t h e p r e s ­ e n t s t a t u s o f h e a r in g i n f i n d i n g o u t t h e t y p e s o f t e s t i n g w h ic h w ere b e in g u s e d i n o t h e r f i e l d s ,

and i n d e t e r m in in g

th e n a tu re o f t e s t i n g b e s t s u ite d to t h i s

stu d y .

I n te r v ie w s

and c o r r e s p o n d e n c e w e r e n e c e s s a r y t o f i n d o u t m ore a c c u r a t e ­ l y fr o m a u t h o r i t i e s o f t h e v a r i o u s f i e l d s

i n v o l v e d , th e s t a n ­

d a rd s o f h e a r in g in v a r io u s o c c u p a tio n s ; t h e p a r t i c u la r t e s t s w h ic h m ig h t be u s e d ; t h e v a r i o u s o t h e r d a t a and t e c h n i q u e s n e c e s s a r y i n t h e s o l u t i o n o f t h e p r o b le m .

The q u e s t i o n n a i r e

m eth o d w as u s e d i n o r d e r t o l e a r n i f t h e s t u d e n t s c o n s i d e r e d th a t t h e ir p r o g r ess in

s h o r th a n d had b e e n du e t o d e f e c t i v e

h e a r i n g ; t o f i n d o u t s o m e th in g o f t h e h i s t o r y o f t h e im p a ir ­ m en t; and t o a s c e r t a i n t h e d e g r e e o f i n t e r e s t w h ic h th e

stu -

d e n t s had i n g e n e r a l to w a r d s t h e s u b j e c t and t h e i r a m b it io n s o f f u t u r e em p loym en t i n t h e c o m m e r c ia l f i e l d . se r v e in th e

c a s e s t u d y m eth od a s a p o s s i b i l i t y

T h is h e lp e d t o as to th e na­

t u r e o f t h e im p a ir m e n t o f t h o s e witJjL d e f e c t i v e h e a r i n g .

The

e x p e r i m e n t a l m eth o d w as u s e d i n s t u d y i n g tw o g r o u p s o f s t u ­ d e n t s o f t h e sam e s e x , sam e g r a d e , s i m i l a r i n a g e , s i m i l a r in th e s t a t u s o f I .

Q .’ s , who had a l l c o v e r e d t h e same m a te ­

r i a l i n t h e sam e am ount o f tim e i n t h e i r s t u d y o f A ls o , s in c e th e s e

sh o rth a n d .

c h i l d r e n had p u r s u e d t h e s t u d y u n d er a t

le a s t fo u r se p a r a te te a c h e r s ,

i t w as c o n s i d e r e d b e s t t o g i v e

th em a s t a n d a r d s h o r th a n d t e s t t o f i n d o u t t h e i r l e v e l o f a c h ie v e m e n t .

The s t a t i s t i c a l m eth o d w as u s e d i n m ak in g t h e

.c o m p a r is o n s o f t h e g r o u p who had f a i l e d w i t h t h e on e w h ic h had c o m p le te d t h e w ork v e r y s u c c e s s f u l l y a s w e l l a s i n com­ p u tin g t h e t e n t a t i v e

sta n d a r d o f h e a r in g .

A m e d i c a l , or

o t o l o g i c a l e x a m in a t io n w as g i v e n t o t h o s e s t u d e n t s w h o se h e a r i n g sh ow ed a n im p a ir m e n t b e y o n d t h e n o rm a l l e v e l u s u a l l y a s ­ s i g n e d , o r 10 d e c i b e l s .

The c h i l d w as in fo r m e d o f t h e n a t u r e

o f t h e im p a ir m e n t, and v a r i o u s r e m e d ia l r e c o m m e n d a tio n s made w h ic h w o u ld p r o b a b ly d e c r e a s e t h e e x t e n t o f t h e h a n d ic a p and m ake t h e c h i l d m ore e f f i c i e n t . I n sum m ary, i t w a s t h e p u r p o s e o f t h i s s t u d y 1) t o d e t e r m in e w h at p e r c e n t a g e o f t h e s t u d e n t s f a i l i n g h ad h e a r in g l o s s e s ;

2) t o

s h o r th a n d

com pare t h e s c o r e s o f t h e h e a r in g

t e s t s w i t h t h e f i n a l s h o r th a n d g r a d e s ;

3) t o d e t e r m in e a

t e n t a t i v e minimum s ta n d a r d o f h e a r in g fr o m t h e s t u d y a s w e l l a s o f o t h e r s w h ic h s t u d e n t s s h o u ld p o s s e s s b e f o r e t a k i n g up t h e s t u d y o f s h o r th a n d ; 4 ) t o s e t up a c r i t e r i o n f o r u s i n g t h e h e a r in g t e s t a s a g u id e by w h i c h - s t u d e n t s e n t e r i n g s h o r t ­ hand may b e t e s t e d

f o r im p a ir e d h e a r in g a f t e r t h e recom m en­

d a t i o n s o f im p a irm e n t h a v e b e e n made b y a n o t o l o g i s t .

W ith

t h i s t e n t a t i v e g a g e , t h e norm may be e s t a b l i s h e d a n d may s e r v e a s a g u id e f o r s h o r th a n d t e a c h e r s i n s e l e c t i n g t h o s e s t u d e n t s w h o se h e a r in g may w a r r a n t t h e i r b e c o m in g e f f i c i e n t ste n o g r a p h er s * R e l a t e d p r o b le m s . As t h e g o a l o f m o st s t e n o g r a p h ic stu d e n ts i s

a c h i e v e d by m eans o f a m u l t i p l e h i g h l y c o m p li­

c a t e d and i n t e r r e l a t e d a b i l i t i e s ,

t e a c h e r s and e d u c a t o r s

h a v e p o i n t e d o u t some o f t h e p r o b le m s i n v o l v e d . h a s p o i n t e d them o u t i n t h i s s t o o d t h a t h e a r in g i s

The w r i t e r

stu d y so th a t i t w i l l be under­

ojxe o f - t ie g r e a t many f a c t o r s

in v o lv e d in

t h e s t u d y o f s h o r t h a n d , and t h i s f a c t a c c o u n t s f o r t h e r e l a ­ t i v e l y lo w c o r r e l a t i o n o f h e a r in g and s t e n o g r a p h y . , A v e r y b r i e f and i n t e r e s t i n g sh o r th a n d h a s b een o u t lin e d

summary o f t h e i s s u e s

by D r. J e s s i e

i n t r a n s c r i p t i o n b y D r. S . J . W anous.

in

Graham, and t h o s e

T h e se su m m aries p r e ­

s e n t t h e m o st o u t s t a n d i n g p r o b le m s o f t h e

stu d y o f s te n o g r a ­

p h y a s e d u c a t o r s v ie w e d th em a t t h e tim e o f t h e

stu d y .

"The

6 p r o b le m s and i s s u e s w i t h r e f e r e n c e t o t e a c h i n g p r o c e d u r e s i n s h o r t h a n d a r e fo u n d i n a t l e a s t f i v e a r e a s * 1: " I.

S h o r th a n d s y s t e m s - w h at s h a l l b e l e a r n e d ? Any s h o r th a n d s y s t e m v s h u n d r e d s o f o t h e r s

"11. .

P u p i l p e r s o n n e l - who s h a l l l e a r n i t ? N eed f o r s e l e c t i o n o f p u p i l s , i d e a l v s t h e a c tu a l c la s s p erso n n el

" ill. ....

P s y c h o l o g y - how. i s i t le a r n e d ? H a b it f o r m a t io n v s p r o b le m s o l v i n g W h ole m eth od v s p a r t m eth od R a p id - b u t - s u r e v s i n d i r e c t m e th o d s O th e r e x p r e s s i o n s and b e l i e f s a s t o how p u p i l s l e a r n s h o r th a n d

" IV .

M easu rem en t - how a r e s k i l l s m ea su r ed ? L o n g -tim e p e r fo r m a n c e m e a su r e d b y f i n i s h e d p r o d u c t v s t h e e v id e n c e o f a c c o m p lis h m e n t o v e r a p e r i o d o f t im e

"V.

E m ploym ent - w hat u s e i s t o b e made o f t h e s k ills ? " -L B u s in e s s sta n d a r d s v s s c h o o ls s ta n d a r d s

D r . W anous a l s o t i o n under f i v e " I. " II.

c la s s i f ie s th e is s u e s in tr a n s c r ip ­

d iv is io n s :

What i s t h e n a t u r e o f t r a n s c r i p t i o n ? When s h o u ld t r a n s c r i p t i o n i n s t r u c t i o n b e g in ? Among t e a c h e r s who s u b s c r i b e t o t h e p o i n t o f-v ie w th a t tr a n s c r ip tio n i s a fu s io n o f s e v ­ e r a l o t h e r s k i l l s and t h a t t r a i n i n g i n i t s h o u ld be s t a r t e d l a t e i n th e s te n o g r a p h ic c o u r se a r e O d e l l , H a r r is o n , L e s l i e , H e w i t t , and o t h e r s .

1

J e s s i e Graham, " In S h o r th a n d ." (B o w lin g G r e e n , K y .: S e v e n t h Y e a rb o o k o f t h e N a t i o n a l B u s i n e s s E d u c a tio n A s s n . , 1941) p p . 3 1 0 -3 1 5 .

7 The i d e a l o g y t h a t t r a n s c r i p t i o n i s a new s k i l l and t h a t t r a i n i n g i n i t s h o u ld b e s t a r t e d e a r l y i n t h e p u p i l s * p rogram o f s t u d y i s cham­ p io n e d b y S l i n k e r , S k im in , W in d e r , Bowman, R e i e r s o n , and o t h e r s , " III. ~ .

How s h o u ld E n g l i s h w e a k n e s s e s i n t r a n s c r i p t i o n b e h a n d le d ? E n g l i s h e r r o r s a r e m ore nu m erou s t h a n t h o s e o f o th e r s u b je c ts . I n a s t u d y made b y D r. W anous o f 1070 p u p ils r e p r e s e n tin g 34 se c o n d a r y s c h o o ls , he fo u n d i n o r d e r o f r a n k , t h e f o l l o w i n g p e r c e n t ­ a g e s o f t o t a l e r r o r s m ade: E n g lis h . . . . . . . . . . 5 5 .1 6 C o n t e n t .............................. 2 7 .3 7 T y p o g r a p h i c a l ..................................... 9 . 3 3 L e t t e r M e c h a n ic s . . . . . 8 .1 4 T e a c h e r s u s e v a r i o u s m e th o d s i n th e h a n d l i n g o f t h e E n g lis h d i f f i c u l t y . Some do n o t f e e l t h a t t h e y a r e a p r o b le m o f t h e C om m ercial D e p a r t ­ m e n t, an d do n o t c o n c e r n t h e m s e l v e s w i t h E n g l i s h errors. O th e r s i n v e s t i g a t e t h e h i g h s c h o o l E n g lis h g r a d e s or th e g r a d e s o f th e p r e v io u s s e m e s t e r b e f o r e l e t t i n g s t u d e n t s e n t e r t h e com­ m e r c ia l c l a s s e s . Some c o m m e r c ia l t e a c h e r s c o n ­ d u c t c o m p r e h e n s iv e e x a m in a t io n s w h i l e o t h e r s c o o p e r a t e w i t h t h e E n g l i s h D ep artm en t i n a s s i g n ­ i n g r e m e d ia l w o r k .

"ITT.

What i s a m a i l a b l e l e t t e r ? f,( l )

E o llo w s v e r y c l o s e l y t h e t h o u g h t o f t h e d ic ta tio n .

" (3 )

C o n t a in s n o u n c o r r e c t e d e r r o r s su c h a s m i s s p e l l in g s , ty p o g r a p h ic a l e r r o r s , i n ­ c o r r e c t p u n c tu a tio n , in c o r r e c t s y l l a b i ­ fic a tio n .

" (3 )

L ook s r e a s o n a b l y n e a t .

”(4 )

C o n t a in s no o m i s s i o n s , s u c h a s an e n t i r e c la u s e or s e n te n c e in th e body o f th e l e t t e r , o r s u c h a s t h e o m i s s i o n o f th e d a t e , t h e s a l u t a t i o n , and t h e c o m p li­ m e n ta r y c l o s e .

8

”V.

W1lat p r o d u c t i o n s t a n d a r d s h o u ld h e a t t a i n e d ? W anous fo u n d t h a t t h e m ed ia n p r o d u c t i o n s ta n d a r d w as a t t h e t r a n s c r i p t i o n r a t e o f 1 4 . 1 w o r d s p e r m in u te .o n t h e a b o v e m e n tio n e d stu d y . The n a t i o n a l ,O ff i c e M anagement A s s o ­ c i a t i o n fo u n d a r a n g e o f fro m 1 2 t o 20 w o rd s p e r m in u te ." 1

W ith s o m any d i v e r g e n t v i e w s c o n c e r n in g t h e m e th o d s o f t e a c h in g , p u p il p e r s o n n e l, p s y c h o lo g y , sta n d a r d s o f m easu re­ m en t and em p loym en t a s t h e s e , a lo n g w i t h nu m erou s o t h e r p r o b le m s , i t

i s n o t s u r p r i s i n g t h a t t h e g o v e rn m e n t an d o t h e r o r ­

g a n iz a t io n s a r e ev en b r o a d c a s tin g f o r e f f i c i e n t

ste n o g r a p h er s.

W here h a v e a l l t h o s e u n em p lo y ed s t e n o g r a p h e r s o f t h e d e p r e s ­ s io n gone?

H ave t h e y b e e n a b s o r b e d b y b u s i n e s s and m arriage*?

O r, m u st i t

be a d m it t e d t h a t t h e r e w e r e many who w e r e ^ n o t em­

p lo y a b le ?

F o r y e a r s b u s i n e s s e d u c a t i o n h a s b e e n i n th e e x p e r ­

i m e n t a l s t a g e , and s t i l l

is ,

but i t

i s t o b e h o p ed t h a t b e f o r e

l o n g i t w i l l b e m ore f i r m l y g r o u n d e d i n t h e e d u c a t i o n a l p ro g ram o f our s c h o o ls .

D r. V i e r l i n g K e r s e y , S u p e r in t e n d e n t o f L os

A n g e le s S c h o o l s , i n t h e b e g i n n in g w o rd s o f an a d d r e s s d e l i v e r e d t o t h e S e v e n t h A n n u a l C a l i f o r n i a C o n fe r e n c e o f B u s i n e s s E d u c a ­ t i o n e x p l a i n e d t h e im p o r ta n c e o f t h i s f i e l d

i n t h e s e w o r d s:

”T h e r e i s n ft a n y p h a s e o f o u r e n t i r e e d u c a ­ t i o n a l p ro g ra m t h a t i s d e v e l o p i n g a s c h a l l e n g i n g l y a s i s b u s in e s s e d u c a tio n . . . . T od ay t h e c h a l l e n g e s i n t h e f i e l d o f b u s i n e s s e d u c a t i o n o u t s t r i p t h e c h a l l e n g e s w h ic h we f i n d i n a n y o t h e r p h a s e o f o u r e d u c a t i o n a l p r o g r a m .” . . " I S . 1 . W anou s, ”I n T r a n s c r i p t i o n . ” ( B o w lin g G r e e n , K y .: S e v e n th Y earb ook o f th e N a tio n a l B u s in e s s T e a c h e r s A ssn . 1941) p p . 3 1 6 -3 2 2 .

He f a r t h e r e x p l a i n s t h a t t h e s e th r ee fa c to r s :

c h a l l e n g e s a r e da© t o

1) a g r e a t e r p e r c e n ta g e o f t h o s e t a k in g b u s i­

n e s s e d u c a t io n , 2) a g r e a t e r p e r c e n ta g e o f t h o s e f in d in g p la c e ­ m ent a f t e r t r a i n i n g , and 3) t h e l a r g e p e r c e n t a g e o f t h o s e who c o n s ta n tly fin d th e need f o r r e t r a in in g .1 A l l k i n d s o f s t a t i s t i c s h a v e b e e n c o m p ile d b y s t u d e n t s o f r e s e a r c h and e d u c a t o r s i n m ak in g a n a l y s e s a s t o why t h e s e c h a lle n g e s a re d i f f i c u l t

to m e e t.

M ost o f t h e

s t u d ie s te n d

t o a g r e e t h a t many o f t h e e r r o r s a r e due t o a c a d e m ic s u b j e c t s a s E n g l i s h and s p e l l i n g , w h i l e som e a t t r i b u t e t h e d e f i c i e n c y to

in te llig e n c e ,

s k ills ,

d e s c r i b e s tw o s e t s

and o t h e r f a c t o r s i n v o l v e d .

T u rse

o f a b i l i t i e s n e c e ssa r y fo r ste n o g r a p h y .

One

g r o u p i s n e c e s s a r y t o l e a r n t h e s h o r th a n d s y m b o ls - t h o s e n e c e s ­ s a r y t o r e c o r d s h o r t h a n d fr o m t h e d i c t a t i o n .

T here a r e :

"good

h e a r i n g , m a n u a l d e x t e r i t y , m o to r and m u s c u la r c o n t r o l , a b i l i t y t o make f i n e d i s c r i m i n a t i o n s i n p r o p o r t i o n and s l a n t s y m b o ls .

The o t h e r g r o u p o f a b i l i t i e s

s e n s e fro m r e c o r d e d s y m b o ls .

in a b str a c t

i s n e c e s s a r y t o make

T h is i s t h e a b i l i t y to

rep rod uce

t h e u t t e r e d th o u g h t o f t h e s p e a k e r b y m a k in g a s s o c i a t i o n s b e ­ t w e e n t h e p h o n e t i c and l i t e r a l s p e l l i n g

o f w o r d s , a k n o w le d g e

1 V i e r l i n g K e r s e y , " G r e e t in g s fro m L os A n g e le s C i t y S c h o o l s . " . S a c r a m e n to : C a l i f o r n i a S t a t e D ep a rtm en t o f E d u c a ­ t i o n , B u r e a u o f B u s i n e s s E d u c a t i o n , B u l l e t i n Mo. 1 , “f a c i n g the" E a c t s i n B u s i n e s s E d u c a t i o n , ” 1 9 4 0 - 1 9 4 1 , p . 5 .

o f s e n t e n c e s t r u c t u r e , v o c a b u l a r y , and w ord s e n s e . b e o b s e r v e d t h a t "good h e a r i n g ” i s m e n tio n e d f i r s t a b ilitie s ,

It

i s to

in th e

and t h a t " a s s o c i a t i o n b e tw e e n t h e p h o n e t i c and

l i t e r a l s p e llin g

o f w o rd s” i s in c lu d e d i n t h e se co n d a b i l i t y .

As t h e r e h a s n o t b e e n a n y i n v e s t i g a t i o n c o n c e r n in g th e t a n c e o f h e a r in g i n r e l a t i o n t o

im p o r ­

sh o r th a n d , i t w as th e p u rp o se

o f t h i s s t u d y t o a tte m p t t h e p r o b le m o f h e a r i n g i n o r d e r t o fin d out i f

t h e r e t e n d e d t o b e a c e r t a i n d e g r e e o f h e a r in g

l o s s b e y o n d w h ic h m o st s t u d e n t s f a i l e d

in th e stu d y o f

ste n o g r a p h y . Scope o f th e s tu d y .

T hroughout th e

c o u n tr y p e o p le

a r e w o r k in g on s t a n d a r d s o f h e a r in g f o r v a r i o u s p u r p o s e s . T h is i s a m a jo r p r o b le m c o n f r o n t i n g t h e e n g i n e e r s o f b r o a d ­ c a s t i n g , t e l e p h o n e , e d ip h o n e , h e a r in g a i d s , t e l e v i s i o n , e l e c ­ t r i c i t y , a v ia tio n ,

s u b m a r in e s , v a r i o u s b r a n c h e s o f s e l e c t i v e

j jj

s e r v ic e a s w e ll a s o th e r ty p e s o f in d u s tr y .

E x p e r im e n t s p e r ­

fo rm ed i n t h e s e a r e a s g i v e s o l u t i o n s t o t h e p r o b le m s o f t h e p a r tic u la r f i e l d

a s w e ll a s to

r e l a t e d o n e s , and a l l h a v e

v a r io u s c o n tr ib u tio n s s i g n i f i c a n t t o o th e r s t u d ie s .

For e x ­

a m p le , t h e t e l e p h o n e i n d u s t r y b e g a n w i t h t h e e f f o r t s o f A l e x ­ a n d e r Graham B e l l t o d e s i g n a h e a r in g a i d f o r M rs. B e l l .

The

v a r i o u s c o m p a n ie s h a v e b e e n t r y i n g t o p e r f e c t t h e s y s t e m f o r y e a r s and i n s o d o in g h a v e made a lm o s t a s many s i g n i f i c a n t c o n tr ib u tio n s to

o t h e r f i e l d s a s h a v e b e e n made t o t h e t e l e -

11 phone in d u s tr y .

E ach o f t h e s e s t u d i e s in v o lv e s th e

o f m a c h in e r y w h ic h i s

a p p lic a b le to

in v e n tio n

o t h e r i n d u s t r i e s and h a s

e v e n c r e a t e d some o f th e m . T h e r e f o r e , o n e who h a s made a s t u d y i n o r d e r t o a t t e m p t t o d e t e r m in e a s t a n d a r d o f h e a r in g m u st h a v e s e c u r e d in fo r m a ­ t i o n fr o m t h e s t u d i e s o f i n d u s t r y t o g e t h e r w it h t h o s e o f o t o l ­ o g y , p s y c h o lo g y , p s y c h ia t r y ,

s t e n o g r a p h y , and b u s i n e s s and

e d u c a tio n a l p h ilo s o p h y . I m p o r ta n c e o f t h e s t u d y . t r a n s a c t i o n s h a s made i t

The c o m p l e x i t y o f b u s i n e s s

n e c e s s a r y f o r b u s i n e s s men t o

s t e n o g r a p h e r s who a r e e f f i c i e n t .

T h is demand on em p lo y m en t

h a s c a u s e d s t e n o g r a p h y t o becom e p e r h a p s o n e o f t h e v o c a tio n s .

e m p lo y

la r g e s t

T h ere w ere 4 ,0 2 5 ,3 2 4 p e o p le en g a g ed i n c l e r i c a l

o c c u p a tio n s in 1 9 3 0 . 1

It

is d iffic u lt

t o d e t e r m in e how many

w e r e h o l d i n g s t e n o g r a p h i c p o s i t i o n s w hen t h e s t u d y w a s u n d e r ­ t a k e n , b u t due. t o v a r i o u s e c o n o m ic f a c t o r s i n v o l v e d ,

it

is

p o s s i b l e t h a t t h e num ber w a s t w i c e t h a t am ount a t t h a t t i m e . C o n s e q u e n t ly , t h e b e s t

ju s tific a tio n

f o r th e t e a c h in g o f sh o r t

h a n d , d i c t a p h o n e , s t e n o t y p e , and r e l a t e d s t u d i e s i s

fo r th e ir

c o m m e r c ia l u s e , and a h ig h d e g r e e o f a c c u r a c y i s n e c e s s a r y i n

U . S . Summary, .O c c u p a tio n a l S t a t i s t i c s , F i f t e e n t h C e n s u s o f t h e U n it e d S t a t e s , W a s h in g to n , D. C . , U . S . D e p a r tm e n t o f Com m erce, B u r e a u o f C e n s u s , 1 9 3 0 , T a b le I I ,

p . 8.

12 o r d e r f o r s t e n o g r a p h y t o b e o f c o m m e r c ia l v a l u e . As new i n d u s t r i e s a r e c o n s t a n t l y i n c r e a s i n g t h e demand f o r s t e n o g r a p h e r s , and a s t h e r e a r e many d r o p p in g o u t i n sh o r th a n d c l a s s e s ,

it

i s n e c e s s a r y t h a t e d u c a t o r s and t e a c h ­

e r s t o g e t h e r f o c u s t h e i r a t t e n t i o n on t h i s p r o b le m i n o r d e r t o e l i m i n a t e t h e l o s t m o tio n i n t e a c h i n g , m a la d ju stm en b s t u d e n t s i n c l a s s e s and i n l a t e r l i f e ,

of

an d t o d e c r e a s e t r e ­

m en dou s a d m i n i s t r a t i v e e x p e n s e s . B y s e t t i n g up a minimum s t a n d a r d o f h e a r i n g ,

it

is

a ssu m ed t h a t t h e r e w o u ld b e a r e d u c t i o n o f s h o r th a n d f a i l ­ u res.

S t u d e n t s w i t h im p a ir e d h e a r in g may b e s a v e d a g r e a t

d e a l o f t i m e , e f f o r t , and e x p e n s e w h ic h c o u ld b e b e t t e r d i ­ r e c t e d t o t r a i n i n g i n t h o s e o c c u p a t i o n s i n w h ic h t h e y w o u ld s e c u r e a more h a p p y and c o m p le te l i v i n g .

I t is

w e l l known

t h a t many p e r s o n a l i t y d i s o r d e r s and a b n o r m a l i t i e s a r e m a n i­ f e s t e d i n y o u n g a d u l t s a f t e r t h e y h a v e e x p e r i e n c e d th e

sh ock

o f l e a r n i n g o f t h e d e f e c t o f t h e i r h e a r i n g m e c h a n ism .

T h is

i s p a r t i c u l a r l y t r u e a f t e r t h e s t u d e n t s h a v e c o m p le te d t h e i r t r a i n i n g and a r e m e a su r e d b y a c t u a l s t a n d a r d s o f b u s i n e s s r a t h e r th a n t h o s e o f e d u c a t i o n .

T h ey f i n d t h a t t h e p a t i e n t

v o i c e o f t h e i r t e a c h e r who w a s u s e d t o d i c t a t i n g t o p e r h a p s a h u n d red o r s o s t e n o g r a p h ic

s tu d e n ts d a i l y , t o be e n t i r e l y

d i f f e r e n t fro m t h a t o f t h e i r new e m p lo y e r and t h e y b e g i n t o r e a liz e

t h a t s o m e th in g i s w rong w i t h t h e i r h e a r i n g .

t h e y d is c o v e r t h a t t h e i r h e a r in g i s

When

so im p a ir e d t h a t t h e y

c a n n o t h o l d a job i n t h e f i e l d

i n w h ic h t h e y h a v e b e e n

t r a i n e d , t h i s s h o c k may becom e m a n i f e s t e d i n n u m ero u s w a y s w h ic h a f f e c t t h e i r e n t i r e p e r s o n a l i t i e s . T h i s m a c h in e a g e w i t h i t s many w o n d e r f u l i n v e n t i o n s h a s d on e much t o w a r d s d e t e c t i n g many c h a r a c t e r i s t i c s o f th e m ec h a n ism b y w h ic h we h e a r .

P e r h a p s m ore d i s c o v e r i e s h a v e

b e e n made r e l a t i v e t o t h e s e n s e o f h e a r in g d u r in g t h e p a s t t e n y e a r s th a n h a v e b e e n made i n a n y o t h e r f i e l d . provem ent i s

T h is im ­

o b served in su ch in d u s t r ie s a s a i r c r a f t ,

r in e s , r a d io , t e l e v i s i o n , many o t h e r f i e l d s

subm a­

t e l e p h o n e , h e a r in g a i d s , and i n

i n v o l v i n g v o i c e r e c o r d in g and h e a r i n g .

H ow ever, n o t a l l o f t h e s e in v e n t io n s have b een h e lp ­ f u l to th e s e n s e o f h e a r in g .

W ith t h e s e m e c h a n ic a l i n v e n ­

t i o n s m any n o i s e s h a v e b e e n c r e a t e d w h ic h h a v e done much i n d e s t r o y i n g f o r m any p e o p l e s o u n d s w h ic h t h e y can n e v e r h e a r a g a in w ith t h e i r n a t u r a l e a r s .

T h i s p r o b le m i s

a c h a lle n g e

t o g u id a n c e p r o g r a m s f o r a t e c h n i q u e b y Tflhich t h o s e who h a v e t h e k e e n e s t p e r c e p t i o n o f h e a r in g may b e s e l e c t e d f o r c a r r y ­ i n g on t h o s e i n d u s t r i e s i n w h ie h i t c ie n c y i s tio n

is

r e q u ir e d , fo r

e ffi­

e f f e c t e d i n many i n d u s t r i e s o n l y th r o u g h t h e

s e le c ­

o f t r a in e d p e r s o n n e l. A n a ly s is o f th e s t u d y .

A f t e r h a v in g made a l i b r a r y

s u r v e y o f th e m a t e r i a l a v a i l a b l e a m a ilin g l i s t

on t h e s t u d y o f h e a r in g t e s t s ,

o f v a r io u s s p e c i a l i s t s

i n r e l a t e d f i e l d s w as

14 m a d e, and many l e t t e r s w e r e w r i t t e n ced u re, a v a ila b le t e s t in g ie s ,

e tc .

L ittle

c o n c e r n in g m e th o d s o f p r o ­

d e v ic e s , p a r a l l e l or r e la t e d

h e l p f u l d a ta w as r e c e iv e d .

stu d ­

An a tte m p t w a s

t h e n made t o s e c u r e i n f o r m a t i o n t h r o u g h i n t e r v i e w s w i t h p s y c h o ­ l o g i s t s , p h y s i c i s t s , a u t h o r i t i e s on s p e e c h and h e a r i n g , o t o l ­ o g is ts ,

s c h o o l s f o r t h e d e a f , h e a r i n g l e a g u e s and s i m i l a r

area s. B e c a u s e o f t h e r e l u c t a n c e o f s c i e n t i s t s t o im p a r t s c i e n ­ tific

fa c ts,

and d u e t o t h e f a c t t h a t many w e r e n o t c o n c e r n e d

w i t h the g e n e r a l a d a p t a t i o n o f t h e i r k n o w le d g e t o a f i e l d t h e y h ad l i t t l e

s tu d ie d , i t

s o o n becam e e v i d e n t t h a t t h e b e s t

s o u r c e o f i n f o r m a t i o n w as t h a t o f m e d i c a l , o t o l o g i c a l , and p h y s i c s j o u r n a l s w h er e r e p o r t s w e r e fo u n d o f r e l a t e d s t u d i e s . The g e n e r a l p r o b le m s r e v e a l e d fro m a l l t h e s e v a r i o u s s o u r c e s o f in fo r m a tio n w ere a s f o llo w s : 1.

2.

3.

A lth o u g h t h e r e w as much d i s c u s s i o n a s t o w h e th e r a s p e e c h t e s t o r a p u r e t o n e t e s t w as t h e m ore v a l i d i n t h e t e s t i n g o f s p e e c h , a p u r e t o n e t e s t w as c o n s i d e r e d t h e m ore s c i e n t i f i c f o r b a s e s o f c o m p a r is o n s a s w e l l a s f o r g e n e r a l s c h o o lr o o m u s e u n d e r v a r y in g a c o u s t ic a l c o n d itio n s . E v e n th o u g h i n c o m m e r c ia l s c h o o l s t h e r e w a s a m ore s e l e c t i v e g r o u p o f s t u d e n t s vd iose i n ­ t e r e s t s w e r e p r i m a r i l y v o c a t i o n a l and who m ig h t have b een ch o sen b eca u se o f a p titu d e f o r s te th ­ n o g r a p h y , i t w as c o n s i d e r e d b e s t t o s e l e c t a m ore n o r m a l g ro u p o f s t u d e n t s t y p i c a l o f t h e s t e n o g r a p h i c d e p a r tm e n t o f t h e p u b l i c s e c o n d a r y s c h o o l. A s many s t u d e n t s who becam e d i s c o u r a g e d i n s h o r t h a n d u s u a l l y d r o p p ed o u t a t t h e en d o f

15 t h e f i r s t and s e c o n d s e m e s t e r s o f b e g i n n i n g s h o r t h a n d , i t w as d e c id e d t h a t a t e s t g i v e n a t t h e end o f t h e s e s e m e s t e r s w o u ld p r o b a b ly f u r n i s h m ore r e l i a b l e d a t a f o r t h e s t u d y , 4.

I t w as d e c id e d t h a t s t u d e n t s s e l e c t e d fr o m tw o s c h o o l s t a k e n a t random w e r e p e r h a p s m ore r e l i a b l e t h a n t o t a k e th em a l l fr o m t h e sam e s c h o o l ,

5.

In ord er t o condu ct a t e s t o f t h i s n a tu r e , i t w as n e c e s s a r y to have th e c o o p e r a tio n o f th e B o a rd o f E d u c a t io n , o f t h e D ep artm en t o f Com­ m e r c i a l E d u c a t io n , o f t h e H e a lt h D ep artm en t , o f t h e tw o s c h o o l s i n -w h ich t h e t e s t s w ere t o be g iv e n in c lu d in g th e p r i n c i p a l s , h ea d s o f d e p a r t m e n t s , and p a r t i c u l a r l y o f t h e t e a c h e r s and t h e s t u d e n t s . The r e l u c t a n c e on t h e p a r t o f a n y o n e i n t h e tw o s c h o o l s m ig h t ham per t h e p r o c e d u r e , and m ake t h e e n t i r e p l a n i m p o s s i b l e to p u rsu e.

6.

T he u s e o f a r e l i a b l e in s t r u m e n t # i i c h m et t h e r e q u ir e m e n t s o f t h e B u r e a u o f S ta n d a r d s i n W ash­ i n g t o n w as i n d i s p e n s a b l e i n a t e s t o f t h i s n a tu r e .

7.

The s e r v i c e s o f a t r a i n e d t e c h n i c i a n and an o t o l o g i s t who w e r e s u f f i c i e n t l y t r a i n e d i n t e s t ­ i n g and i n d e a l i n g w i t h s e c o n d a r y s c h o o l s t u ­ d e n ts w ere r e q u ir e d .

8.

A q u i e t room i n e a c h s c h o o l w a s a b s o l u t e l y e s ­ s e n t i a l f o r c o n d u c t in g t h e t e s t s .

9.

An o t o l o g i c a l e x a m in a t io n i n c l u d i n g a b o n e c o n d u c to r and a s p e e c h t e s t , or t h e w h is p e r e d v o i c e t e s t w a s i m p e r a t i v e f o r R e v e a l i n g h e a r in g d e f e c t s in o rd er to stu d y th e n a tu r e o f th e h e a r i n g im p a ir m e n t.

10.

M o n ito r s w e re n e e d e d i n g e t t i n g t h e s t u d e n t s fr o m t h e i r c l a s s e s and i n o r g a n i z i n g th e s t u ­ d e n t s s o t h a t t h e y c o u ld r e p o r t t o t h e o t o l o g i s t and t h e a u d i o m e t r i s t a t t h e p r o p e r t i m e .

11.

D a ta m u st b e s e c u r e d fr o m t h e p erm a n en t r e c o r d c a r d s a f t e r t h e f i n a l g r a d e s had b e e n r e c o r d e d , and i n som e c a s e s i t w a s n e c e s s a r y t o c o n s u l t

16 th e te a c h e r s* grade books in o rd er t o f in d o u t m ore a b o u t c e r t a i n s t u d e n t s * 12.

I t w a s c o n s i d e r e d t h a t an a c h ie v e m e n t t e s t s h o u ld b e s e c u r e d and g i v e n w h ic h w as d e ­ s i g n e d p a r t i c u l a r l y a s a f i n a l e x a m in a t io n . s o t h a t t h e r e w o u ld be a m ore a c c u r a t e b a s i s f o r c o m p a r is o n t h a n t h a t o f s h o r t h a n d g r a d e s a lo n e .

13.

A q u e s t i o n n a i r e m u st b e p la n n e d an d g i v e n t o th o s e stu d e n ts t o a s c e r ta in th e h is to r y o f h ea r i n g im p a ir m e n ts w h ic h may h a v e b e e n fo u n d i n t h o s e ^ s h o w in g d e f e c t s a s w e l l a s to d e t e r m in e t h e i n t e r e s t w h ic h t h e s t u d e n t s h ad i n t h e stu d y .

14.

C o m p r e h e n siv e s u r v e y s w e r e n e c e s s a r y i n s h o r t ­ h a n d , s p e e c h , and h e a r in g i n o r d e r t o b u i l d a background f o r th e s tu d y .

15.

V a r io u s c o m p a r is o n s and c o m p u t a t io n s w e r e n e c ­ e s s a r y b e f o r e a s t a n d a r d c o u ld b e f o u n d .

16.

I t w a s n e c e s s a r y t o s e c u r e t h e n ew t a b l e s o f c o m p u tin g s t a n d a r d s w h ic h w e r e a d o p te d b y t h e A m e rica n M e d ic a l A s s o c i a t i o n i n J u n e 1 9 4 2 .

17.

O t o l o g i s t s and s t a n d a r d s a s s o c i a t i o n s w e r e c o n s u l t e d b e f o r e a f i n a l s t a n d a r d w as d e ­ te r m in e d .

V a l i d a t i o n and n e e d o f f u r t h e r s t u d y . stu d y o f t h i s t e s t in g

p r o c e d u r e , i t w as ap p aren t t h a t fo r a

num ber o f r e a s o n s t h a t t h i s v a lid .

s t a n d a r d c o u ld n o t b e a c c e p t e d a s

I t w as t h e p u r p o s e o f t h i s

te n ta tiv e

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its

set

a minimum

p u rp ose.

T h is

i s n o t a s t a n d a r d t o b e u s e d i n th e c la s s r o o m , b u t i t i s h o p ed t h a t v a r i o u s s c i e n t i s t s w i l l make t h e i r c o n t r i b u t i o n s t o th e im p e r fe c tio n s o f t h i s

s t u d y , and t h a t i n t h e n e a r

fu ­

t u r e e x p e r im e n t s w i l l be c a r r i e d o u t on h u n d r e d s o f s t e n o g -

17 r a p h e r s and s t e n o g r a p h i c s t u d e n t s w h ic h w i l l s e t t l e

th is

i m p e r a t i v e dem and. L im it a t io n s o f th e e x p e r im e n t. ite d by th e v e r y n a tu r e of th e

T h is s t u d y w as limr%:

s u b j e c t o f h e a r in g t r e a t e d ,

t h e num ber o f t e s t s g i v e n , t h e g r o u p o f s t e n o g r a p h ic s t u d e n t s s e l e c t e d , th e r e l a t i v e n ew n ess o f th e m a t e r ia l c o n fin e d t o th is

s t u d y a s w e l l a s b y t h e w r i t e r ’ s l i m i t e d k n o w le d g e i n

t r e a t i n g a l l th e v a r io u s r e l a t e d f i e l d s

o f th e in v e s t ig a t io n .

As m o st o f t h e s c i e n t i f i c m a t e r i a l c o n c e r n in g s u r v e y s o f t h e v a r i o u s a u d io m e t e r and s p e e c h t e s t s w e r e p u b l i s h e d w h i l e t h e t h e s i s w as i n p r o g r e s s due t o t h e p e c u l i a r n e w n e s s of s c ie n tific a lly

c o n t r o l l e d h e a r in g t e s t s , much o f t h e d a t a

c o l l e c t e d h ad b e e n p u b l i s h e d s i n c e t h e b e g in n in g o f t h e 1 9 4 0 decade.

Many f i e l d s w e r e s t i l l a w a i t i n g i n v e s t i g a t i o n b e f o r e

o c c u p a t i o n a l h e a r in g n orm s c o u ld b e s c i e n t i f i c a l l y

e s ta b lis h ­

ed. As t h e p la n o f th e i n v e s t i g a t i o n p r o g r e s s e d ,

it

w as

fo u n d a b s o l u t e l y n e c e s s a r y t o t r a c e t h e v e r y i n t r i c a t e p r o e - e s s e s i n v o l v e d i n t h e p e r fo r m a n c e o f s p e a k i n g , h e a r i n g , ste n o g r a p h y a lo n g w ith th e r e l a t i v e

and

s t u d ie s o f p h y s io lo g y ,

p s y c h o l o g y , a c o u s t i c s , and o t o l o g y , and t o l e a r n s o m e th in g o f t h e i r i n t e r r e l a t e d n e s s w i t h on e a n o t h e r .

T he s t u d y made

n o a t te m p t t o d e a l w i t h s p e e c h , h e a r i n g , a n d s t e n o g r a p h i c d e f i c i e n c i e s e x c e p t in m ent o f h e a r i n g .

so f a r a s t h e y a f f e c t e d t h e m e a s u r e ­

I t w as n e it h e r co n cern ed p a r t i c u l a r l y w ith

18 t h e v a r i o u s w ays i n w h ic h im p a ir m e n ts m ig h t b e a l l e v i a t e d i n t h e s c h o l a s t i c an d o c c u p a t i o n a l p r o g r e s s o f s t u d e n t s . B r i e f l y s t a t e d , th e t e s t w as r e s t r i c t e d

to stu d e n ts

o f t h e L o s A n g e le s C i t y S c h o o l s y s t e m r e p r e s e n t i n g t h e M anual A r t s and t h e S u sa n D o r s e y s e c o n d a r y p u b l i c

s c h o o ls , o f th e

f e m i n in e s e x , who h ad c o m p le te d one s e m e s t e r or tw o s e m e s t e r s , o r SO w e e k s o r 4 0 w e e k s o f f i f t y - f i v e m in u te p e r i o d s o f f i v e d ays a w eek , o f th e f i r s t y e a r o f sh o rth a n d . s t u d e n t s v a r i e d fro m 1 5 t o 16 y e a r s o f a g e .

The a g e s o f t h e

1 8 y e a r s , b u t m o st o f them w e r e

I n t h e M anual A r t s H ig h S c h o o l , t h e g i r l s

fr o m t h r e e s h o r th a n d c l a s s e s w e r e s e l e c t e d .

T w e n ty -fiv e w ere

s e l e c t e d a s t h e b e s t s t u d e n t s and t w e n t y - f i v e w e r e t o b e r e p ­ r e s e n ta tiv e

o f t h e l o w e s t fr o m t h e t h r e e c l a s s e s .

H o w e v er ,

i t w a s l a t e r fo u n d by t h e d i s t r i b u t i o n o f t h e g r a d e s t h a t t h i s p r o c e d u r e w as n o t s t r i c t l y f o l l o w e d . S c h o o l , a l l o f t h e s t u d e n t s o f b e g in n in g th e seco n d se m e ste r w ere t e s t e d . th e I .

£ . fa cto r

I n t h e D o r s e y H ig h s h o r th a n d c o m p le t in g

I t w as i m p o s s i b l e t o

o r t h e a c h ie v e m e n t f a c t o r ,

c o n tr o l

an d i t w as c o n ­

s i d e r e d - t h a t t h e s e w o u ld n o t a f f e c t p a r t i c u l a r l y th e m e a s u r e ­ m en t o f a n a t i v e c a p a c i t y o f a p u r e - t o n e t e s t i n g

d e v ic e .

Some s c i e n t i s t s a r g u e d a g a i n s t t h e u s e o f t h e a u d i o ­ m e t e r i n t e s t i n g t h e h e a r i n g f o r s p e e c h w h ic h i s

th e b a s is

o f d i c t a t i o n w h e th e r i t w a s done b y s h o r t h a n d s y m b o ls , e d i p h o n e, d ic ta p h o n e , o r s t e n o t y p e .

H o w e v er , s p e e c h t e s t s a r e

e v e n m ore v a r i a b l e i n d e g r e e a s w e l l a s i n k in d e v e n u n d er

19 t h e m o st s c i e n t i f i c a l l y

c o n tr o lle d

c o n d itio n s .

R e c e n tly ,

much h a s b e e n a c c o m p lis h e d i n e s t a b l i s h i n g t h e w e i g h t i n g o f t h e v a r i o u s p h o n e t i c s o f s p e e c h on t h e a u d io m e te r f r e q u e n c y s c a le . O th er f a c t o r s a f f e c t i n g t h e s t u d y a r e b i n a u r a l o r mon­ a u r a l h e a r i n g , o r h e a r i n g w i t h tw o e a r s o r o n e , th e d e g r e e o f h e a r in g a c u i t y b e i n g i n f l u e n c e d b y t h e n a t u r e o f t h e v a r i o u s ty p e s o f p o s s ib le

im p a ir m e n t s .

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th e t y p e ,

n a t u r e , d u r a t i o n o f t h e d e f e c t , p e r s o n a l i t y a d j u s t m e n t s an d c o m p e n s a t io n s , and t h e a g e o f t h e

ste n o g r a p h er .

an d i n t e n s i t y o f p h o n e t i c s r e a c h in g th e e a r i s fa cto r .

T he f r e q u e n c y an im p o r ta n t

A lth o u g h t h e r e w as some r e a c t i o n a g a i n s t a h e a r i n g

a i d b y m any e m p lo y e r s , t h a t t y p e o f a d j u s t m e n t i s b e c o m in g i n ­ c r e a s i n g l y im p o r t a n t m ak in g i t

p o s s i b l e f o r a p p r o x im a t e ly 97

or 98 p e r c e n t o f th e p e o p le to h e a r . The p r o b le m o f a c o u s t i c s r e l a t i n g t o t h e

room i n w h ic h

t h e t e s t w as c o n d u c te d w as c o n s i d e r e d i n t h e t e s t , q u i e t e s t room a v a i l a b l e

o f e a c h s c h o o l w as s e c u r e d .

l a t i o n t o t h i s m u st a l s o be k e p t i n m ind

and t h e In r e ­

t h e d i s t a n c e u n d er

w h ic h t h e d i c t a t o r and t h e s t e n o g r a p h e r w ork a p a r t m o st o f t h e t i m e a s w e l l a s t o w h e th e r t h e s t e n o g r a p h e r i s l e f t h a n d e d , and t h e p o s i t i o n th e p o s itio n

r ig h t o r

of th e b e st ea r in r e la t io n to

o f th e d ic ta to r .

The a u d io m e t e r , t h e a u d i o m e t r i s t , and t h e

su b je c t are

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i s n e c e ssa r y to g iv e a b a tte r y o f t e s t s t o d iffe r e n t

in d iv id ­

u a l s , and t o . t e s t t h e sam e i n d i v i d u a l s a num ber o f t i m e s d u r ­ in g th e in t e r v a l o f a t l e a s t a y e a r . ic

A s a m p lin g o f s t e n o g r a p h ­

s t u d e n t s fr o m a l l p a r t s o f t h e c o u n t r y u n d e r v a r i o u s c o n ­

tr o lle d

c o n d i t i o n s i s n e c e s s a r y i n s t a b i l i z i n g a norm o f m ea­

su r e m e n t o t h e r t h a n a t e n t a t i v e o n e .

I t w as f u r t h e r r e a l i z e d

t h a t som e s t u d e n t s h ad t a k e n a u d io m e t e r t e s t s p r e v i o u s l y , and m ig h t h a v e b e e n m ore c a p a b le o f a d j u s t i n g t h e m s e l v e s t o t h e te s tin g

p r o c e d u r e s t h a n w e r e some o f t h e o t h e r s t u d e n t s . A lth o u g h t h e w r i t e r r e c e i v e d t h e c o u r t e o u s c o o p e r a t i o n

o f t h e t e a c h e r s and s t u d e n t s , an d e v e r y t h i n g p o s s i b l e w a a -h o n e t o c o n t r o l t h e e x p e r im e n t w i t h i n l i m i t a t i o n s , y e t t h e r e w e r e many s h o r t c o m in g s i n t h e p r o c e d u r e w h ic h m ore o r l e s s a r i s e e r y e x p e r im e n t on h e a r i n g .

in e v ­

Some a d j u s t m e n t s w e re made i n com­

p u t i n g t h e s t a t i s t i c s f o r t h e s e d e f i c i e n c i e s , an d i t

w as c o n ­

s i d e r e d t h a t t h e g u id e f o r a minimum s t a n d a r d o f h e a r i n g a s s e t by t h is

e x p e r im e n t w a s n e i t h e r t o o h i g h n o r t o o lo w f o r

m a k in g d i s c r i m i n a t i o n s i n f a v o r o f t h o s e who t h r o u g h t h e i r n a t u r a l a b i l i t y o f a u d i t o r y p e r c e p t i o n w e r e t h e m o st h i g h l y c a p a b le o f c a r r y i n g on t h o s e o c c u p a t i o n s w h ere a c u t e h e a r i n g w a s e s s e n t i a l and p a r t i c u l a r l y t h e one i n w h ic h m i l l i o n s a r e engaged - ste n o g r a p h y .

21

DEFINITIONS OF TERMS USED T e n ta tiv e : Of t h e n a t u r e o f a n a t t e m p t , e x p e r im e n t , o r h y p o t h e s i s t o w h ic h one i s n o t f i n a l l y c o m m itte d . Som e­ t h i n g o f f e r e d o r u n d e r ta k e n p r o v i s i o n a l l y ; u s e d i n m a k in g a t r i a l ; done a s a n e x p e r im e n t . M inimum: The l e a s t i m p r e s s i o n t h a t c a n be p e r c e i v e d by a se n s e f o r a g iv e n p u r p o se , or th e l e a s t p o s s ib le d e g r ee t h a t can be a s s ig n e d in a g iv e n c a se un der a f ix e d c o n d it io n . S t a n d a r d : A d e f i n i t e u n i t b y r e f e r e n c e t o w h ic h o t h e r t e s t s may b e c o m p a r a b le or r e g u l a t e d , A u n i t w h ic h s e r v e s a s a g a g e , t e s t , g u i d e , or m o d e l. Any m e a s u r e or q u a n t i t y o r v a lu e e s t a b l i s h e d b y e x p e r i m e n t a t i o n . A d e fin ite le v e l, de­ g r e e , q u a l i t y v h i c h i s a d e q u a te f o r a g i v e n p u r p o s e . H e a r in g : The a c t o r pow er o f p e r c e i v i n g so u n d ; t o g a i n k n o w le d g e o f th r o u g h t h e e a r ; t h e s p e c i a l s e n s e b y w h ic h sh u n d s a r e p e r c e i v e d t h r o u g h t h e e a r and t r a n s m i t t e d t o t h e b r a in . O to lo g is t:

An e a r s p e c i a l i s t .

E f f i c i e n t S t e n o g r a p h e r : Ima E h r e n h a r d t, o f t h e I n d ia n a S t a t e T e a c h e r s C o l l e g e , d e f i n e s t h e te r m i n t h i s m an n er: What i s m ean t b y t h e te r m ” e f f i c i e n t s t e n o g r a p h e r ” ? Of c o u r s e , a p i c t u r e im m e d ia t e ly f l a s h e s upon t h e ’ i n ­ n e r e y e ’ , a p i c t u r e o f a w e ll- g r o o m e d b o y or g i r l n e a t l y and b e c o m in g ly d r e s s e d ; who h a s a z e s t f o r k n o w le d g e ; who s p e a k s and w r i t e s E n g l i s h c o r r e c t l y ; who h a s a n i n t e r e s t i n l i f e and who k e e p s a b r e a s t w i t h t h e t i m e , who e x e r c i s e s i n i t i a t i v e an d c r e a ­ t i v e n e s s ; who h a s a s e n s e o f hum or; who i s w i l l i n g t o w ork ; a n d , l a s t b u t n o t l e a s t , who p o s s e s s e s j o b c o m p e te n c y i n s t e n o g r a p h ic s k i l l . Can t h e h i g h s c h o o l a d o l e s c e n t s , d ia m o n d s i n t h e r o u g h , so t o s p e a k , a p p r o x im a te t h e d e s c r i p t i o n o f t h e p e r s o n d e s c r ib e d above? 1

1 Ima E h r e n h a r d t , " T r a in in g E f f i c i e n t S t e n o g r a p h e r s , ” ( B o w lin g G r e e n , K y i; F i f t h Y e a rb o o k o f t h e N a t i o n a l Commer­ c i a l ' T e a c h e r s 'F e d e r a t i o n , N a t i o n a l B u s i n e s s E d u c a t io n 0 i t l o o k , ' 19159} p . 2 6 3 .

22

Dae t o t h e t e c h n i c a l n a t u r e o f t h i s s t u d y , b e e n fo u n d n e c e s s a r y t o d e f i n e p la i n i n g th e e x p e r im e n t.

it

has

some o f t h e te r m s u s e d i n e x ­

T h e s e w i l l b e i n t h e G lo s s a r y a t

t h e en d o f t h e t h e s i s . O r g a n iz a t io n o f t h e r e m a in d e r o f t h e t h e s i s .

The

s e c o n d p a r t of t h e s t u d y d e a l s w i t h a r e v i e w o f t h e r e l a t e d lite r a tu r e . fic a tio n

The s t a t u s

o f b u s i n e s s e d u c a t i o n and t h e

o f t h e p r o b le m i s

u n d e r t a k e n i n th e f i r s t

A ls o , th e p r e s e n t s t a t u s o f th e

s c ie n tific

ju s ti­

c h a p te r*

k n o w le d g e o f h e a r ­

in g d e a l i n g p a r t i c u l a r l y w i t h t h e p s y c h o l o g y and p h y s i o l o g y i s g i v e n s o t h a t t h e r e a d e r may b e t t e r u n d e r s ta n d t h e p r o b ­ le m s o f t e s t i n g and h e a r i n g s t a n d a r d s . th e r e la t io n

o f s p e e c h and h e a r in g t o

C h a p te r 3 c o n c e r n s s h o r th a n d w h i l e th e

f o l l o w i n g c h a p t e r e x p l a i n s t h e v a r i o u s m e th o d s w h ic h a r e u s e d i n t e s t i n g h e a r in g ; r e v i e w s o f s u r v e y s and s c h o o l t e s t s th e

some o f t h e im p o r ta n t h e a r in g

a re g iv e n in

C h a p te r 5 , p o r t r a y i n g

im p o r t a n t f a c t s w h ic h t h e y e s t a b l i s h e d

c o n t r ib u t io n s t o t h e a d o p tio n o f th e

in th e g r a d u a l

sta n d a r d o f e s t im a t in g

p e r c e n t a g e h e a r in g l o s s a d o p te d i n J u n e , 1 9 4 2 , a s d e s c r i b e d i n C h a p te r 6 . The t h i r d p a r t i n c l u d e s t h e s o u r c e s o f d a t a a n d t h e v a r i o u s m e th o d s o f p r o c e d u r e u s e d i n c o n n e c t i o n w i t h t h e e x ­ p e r im e n t t o g e t h e r w i t h t h e f i n d i n g s and c o n c l u s i o n s . B i b l i o g r a p h y and t h e G lo s s a r y a r e t o be fo u n d a t t h e th e stu d y .

The en d o f

PART I I REVIEW OP RELATED LITERATURE C h a p te r 1 STATUS OE BUSINESS EDUCATION AND JUSTIFICATION OF THE PROBLEM R e c e n t r e s e a r c h h a s r e v e a l e d t h a t t h e r e a r e n u m erous t y p e s o f h e a r i n g , and t h a t t h e v a r i o u s d e g r e e s o f h e a r in g a f f e c t s p e e c h and t h e h e a r i n g o f s p e e c h i n many d i f f e r e n t w ays.

G e n e r a l l y , s t u d e n t s a r e n o t a w are o f a l o s s u n t i l i t

becom es so c r i t i c a l t h a t t h e y n o t ic e i t

i n t h e a t r e s and a u d i ­

t o r i u m s , and i n c o n s t a n t a s s o c i a t i o n w i t h t h o s e who c a n n o t u n d e r s ta n d th e m .

C o n s e q u e n t ly , m o st o t o l o g i s t s and a u d i o -

m e t r i s t s h a v e fo u n d t h a t fe w p e o p l e

co n c er n th e m s e lv e s w ith

t h e p r o b le m o f h e a r i n g b e f o r e t h e i r h e a r i n g l o s s r e a c h e s a sta g e little

o f b e tw e e n t w e n t y - f i v e and t h i r t y - f i v e c a n b e d on e t o t r e a t i t .

d e c i b e l s when

A nd, e v e n th o u g h m any s t u ­

d e n t s r e a l i z e d t h a t t h e y w e r e u n a b le d t o h e a r w e l l , many f a c ­ to r s r e la tiv e

t o i n t e r e s t and a m b it io n c a u s e d th em t o be d e ­

s i r o u s o f u n d e r t a k in g t h e s t u d y i n s p i t e The m a in o b j e c t i v e o f t h i s

o f t h e i r im p a ir m e n t.

c h a p te r, th e n , is

to

r e la te

t h e p r o b le m o f h e a r i n g t o t h e p r o b le m s , p r a c t i c e s , and p h ir llo s o p h y o f b u s i n e s s e d u c a t i o n i n g e n e r a l , p r o b le m s and p r a c t i c e s o f s t e n o g r a p h y .

and t o t h e p r e c i s e Such a p r o c ed u r e en ­

24 deavors to fo s te r a s c ie n t if ic

a t t it u d e t o a r a th e r r o u tin iz e d

and m e c h a n ic a l p r o c e s s o f e d u c a t i o n , and i t

is

h o p ed t h a t i t

w i l l g i v e t e a c h e r s and e d u c a t o r s a b r o a d e r c o n c e p t i o n o f a r e l a t i v e l y new p o s s i b i l i t y o f a m eth od o f a p p r o a c h t o w hat h a s. v e r y r e c e n t l y becom e o n e o f t h e m o st v i t a l p h a s e s o f o u r e d u ­ c a t i o n a l program * A c c o r d in g ly ,

it

is

n e c e s s a r y to

e x a m in e t h e f i e l d

of

s t e n o g r a p h y and f i n d o u t t h e o b j e c t i v e s , p h i l o s o p h y , and com­ mon p r a c t i c e s o f s t e n o g r a p h y i n d e t e r m i n i n g how t h e y m ig h t be i n f l u e n c e d by, a new a p p r o a c h t o t h e p r o b le m o f s e l e c t i o n o f stu d e n ts.

D r. J e s s ie

sh o rth a n d t e a c h in g i s th e n ,

is

Graham h a s s a i d t h a t ,

"The g o a l o f a l l

v o c a t io n a lly a c c e p ta b le

s h ill."

1

T h is ,

t h e b ro a d o b j e c t i v e to w a r d s w h ic h t e a c h e r s and e d u c a ­

t o r s a r e s t r i v i n g a s w e l l a s to w a r d s th e w o r th and s a t i s f a c t i o n

o b je c tiv e s a t p e rso n a l

in v o lv e d in th e s ta te m e n t.

In order to

r e a c h t h i s g o a l, v a r io u s p r o c e d u r e s in l i n e w ith c u r r e n t p h i lo ­ s o p h i c v ie w s h a v e b e e n a d o p te d by c o m m e r c ia l d e p a r t m e n ts th r o u g h v o c a t io n a l g u id a n c e , s e c u r in g o f q u a l i f i e d

in s tr u c to r s ,

a r r a n g in g c l a s s s c h e d u l e s , g i v i n g p a r t - t i m e t r a i n i n g b y mu­ t u a l l y c o o p e r a t i n g w i t h b u s i n e s s m en , i n m a k in g j o b - s h e e t s o f c o m p le t e i n s t r u c t i o n s t o r ec o r d s of th e

s t u d e n t s , an d i n k e e p in g c o m p le t e

stu d e n ts1 p ro g ress.

1 J e s s ie

Graham,

0£

.

c it .,

p. 315.

T he p r o b le m o f v o c a t i o n a l g u i d a n c e , p a r t i c u l a r l y i n r e la t io n to th e s e le c t io n

of p u p ils i s

s t i l l o n e o f t h e m o st

c h a lle n g in g o f t h o s e o f t h e v o c a t io n a l program .

S tu d ie s

h a v e r e p e a t e d l y e m p h a s iz e d t h e f a c t t h a t m o st o f t h e s t u d e n t s ch o o se ste n o g r a p h y b ec a u se i t w h ic h t h e y l i k e ,

t r a i n s th em f o r a n o c c u p a t i o n

or a r e i n t e r e s t e d

d e s ir a b le ; th e co u rse o f tr a in in g t io n s are u s u a lly p le a s a n t; a d v a n ta g e s. a b ility

i n ; l:t h e r e m u n e r a t io n i s is

b r i e f ; w o r k in g c o n d i ­

and b e c a u s e o f v a r io u s s o c i a l

E v en th o u g h t h e i n t e r e s t f a c t o r i s

im p o r ta n t,

s h o u ld assu m e e v e n g r e a t e r im p o r ta n c e i n an e d u c a ­

t i o n a l p rogram i n w h ich t r a i n i n g i s

v e r y e x p e n s i v e and t i m e -

c o n s u m in g . . P r o f e s s o r F r e d e r i c k G» N i c h o l s h a s made t h e f o l ­ lo w i n g com m ent: I w o n d er i f t h e t im e w i l l n o t come w hen i n t h e 1i n t e r e s t o f s o c i e t y a n d t h e c o n s e r v a t i o n o f o u r l i m i t e d f u n d s f o r e d u c a t i o n an d t h e r i g h t s o f t h e p e o p l e M io a r e i n o u r c l a s s e s , we s h a l l n o t s a y a t l e a s t i n p e r f e c t l y c l e a r e a s e s , nt h o u s h a l t n o t. w 1 A lth o u g h t h e s c h o o l p rogram h a s a t t e m p t e d t o be demo­ c r a tic

i n i t s m e th o d s o f g u i d a n c e , y e a r s o f e x p e r i e n c e h a s

ta u g h t th a t

o n l y b y a program o f s e l e c t i o n

• rea ch th e v o c a tio n a l g o a l.

can ste n o g r a p h y

T h is f a c t h a s b e e n d u p l i c a t e d

1 F r e d e r i c k G. N i c h o l s , -^Comment S on G u id a n ce and C o u n s e l i n g . n R e p o r t o f t h e E ig h t h .A n n u a l C a l i f o r n i a Con­ f e r e n c e on B u sin e ss" HcTtTcation, C a l i f o r n i a S t a t e d e p a r tm e n t o f B u s i n e s s Ed u c a t io r t r iS u r e a ll o f B u s i n e s s E d u c a t i o n , B u lle tin 11 , 1941, p . 35.

26

m any t i m e s i n our s c h o o l s y s t e m .

I t h as been r e c e n tly

v o i c e d b y R a lp h W. H a l l e r , P r i n c i p a l o f t h e A ndrew J a c k s o n H ig h S c h o o l o f Ne?/ Y o r k .

He s t a t e d t h a t t h e f a c t m u st n o t

be o v e r lo o k e d t h a t c o m p e te n c y i s

t h e p r i n c i p a l r e q u ir e m e n t

o f p l a c e m e n t , and t h a t f r e e e l e c t i o n o f s u b j e c t s o f t e n r e ­ s u lts

i n much w a s t e .

He f u r t h e r c o n s i d e r s t h a t

P u p i l s w i t h l e s s th a n a' c e r t a i n d e g r e e o f i n n a t e a b i l i t y s h o u ld b e b a r r e d fr o m t h e s'tu d y o f s t e n o g r a p h y , and p u p i l s who c a n n o t a t t a i n a c e r t a i n d e g r e e o f c o m p e te n c y i n t h e s u b j e c t s h o u ld im m e d ia t e ly be d r o p p e d . S u ch a p r o c e d u r e w i l l , i n t h e e n d , b e k in d t o t h e p u p i l s an d w i l l c e r t a i n l y be f a i r t o t h e C it y and h o n e s t t o t h e p a r e n ts. 1 In c o n s id e r in g th e p r o c e s s e s in v o lv e d i n it

is

r e a l i z e d t h a t m o st o f th em a r e v e i y

to

in te lle c tu a l a b ility .

-e sse s,

it

ste n o g r a p h y ,

c lo s e ly r e la te d

W ith a summary o f t h e m e n t a l p r o c -

i s p o s s i b l e t o v i e w t h e c o m p l e x i t y o f t h e many

f a c t o r s i n v o l v e d i n t h e s t u d y and m a s t e r y o f s t e n o g r a p h y . I n te lle c tu a l a b ilit y

is

A num ber o f s p e c i a l a b i l i t i e s , o f t e n c a l l e d g r o u p f a c t o r s b e c a u s e e a c h one e n t e r s i n t o a b i l ­ i t y i n a w h o le g ro u p o f p e r f o r m a n c e s . It is p r e t t y w e l l e s t a b l i s h e d t h a t su c h a b i l i t i e s a s t h e f o l l o w i n g e x i s t : v e r b a l a b i l i t y , or t h e a b i l ­ i t y t o d e a l w i t h n u m b ers; s p a t i a l a b i l i t y , o r :t h e

1 R a lp h W. . H a l l e r , ,fThe L e g i t i m a t e P i e I d o f S t e n o g r a p h y and T y p in g i n New Y ork C i t y H ig h S c h o o l s .* 1 (New Y ork: The E l e v e n t h Y e a rb o o k o f t h e C om m ercial E d u c a ­ t i o n AssociaTTTon o f t h e C i t y o f - New Y ork and V i c ln r E y l f e u s ln e s s ~ and’ k i i s i n e s s E d u c a ii o n , I § 4 0 ) p . SO.

37 a b i l i t y t o d e a l w ith s p a t i a l r e la t io n s * T h ars t o n e t h i n k s t h a t he h a s d e m o n s tr a te d t h a t i n t e l l e c t u a l a b i l i t y r e a l l y c o n s i s t s o f som e s e v e n t o t w e l v e p r im a r y a b i l i t i e s n in e o f w h ic h h e c a l l s : s p a t i a l v i s u a l im a g e r y , p e r c e p t u a l s p e e d , m em ory, w ord f l u e n c y , num ber f a c i l i t y , in d u c t io n , v e r b a l r e l a t i o n s , d e d u c tiv e r e a s o n in g and r e s t r i c t i o n o f r e a s o n i n g to w a r d s o l u t i o n o f a p r o b le m . ^ I t w i l l b e o b s e r v e d t h a t a l l o f t h e p r im a r y a b i l i t i e s w h ic h T h u r s t o n e h a s r e v e a l e d a r e a p a r t o f th e p r o c e s s e s i n ­ v o l v e d i n s h o r th a n d an d t r a n s c r i p t i o n . a r e m ore o r l e s s f i x e d

S in c e t h e s e a b i l i t i e s

b y t h e tim e t h e s t u d e n t s a t t e m p t s h o r t ­

h a n d , i t w i l l b e u n d e r s t o o d t h a t t h e o n l y m eans o f th is

c o n tr o l in

c o n n e c t i o n w o u ld be n e c e s s a r i l y t h a t o f .p U p il s e l e c t i o n .

As t h e m e n t a l f a c t o r d iffic u lt

to

i n v o l v e s s o many p r o c e s s e s ,

u n d e r s ta n d why p u p i l s e l e c t i o n

it

in ste n o g r a p h y i s

o n e o f t h e l a t e s t t e c h n i c s i n m e th o d s o f g u i d a n c e . S k im in s t a t e d t h a t

i s not

E le a n o r

"Im proved g u id a n c e p ro g ra m s m u st f u n c t i o n

so th a t th e t r a n s c r ip tio n c la s s p o s s e s s th e a b i l i t i e s ,

i s made up o f p u p i l s t h a t

a p t i t u d e s and d e s i r e s n e c e s s a r y t o

make th em p o t e n t i a l l y t r a i n a b l e

e m p lo y e e s f o r s t e n o g r a p h i c

w o r k ." ^

E , B . Van Ofmer and G. 0 . W i l l i a m s , E le m e n ta r y S t a t i s t i c s f o r S t u d e n t s o f E d u c a t io n and P s y c h o l o g y , CEim A r b o r , M ic h ig a n : Edwards~HB r o h h e r s , T n c . , 1 9 4 0 ) p . d 6 . 2 E le a n o r S k im in , " P ro b lem s o f T r a n s c r i p t i o n . " (New Y ork : T h i r t e e n t h Y e a rb o o k o f t h e E a s t e r n C o m m ercia l T e a c h e r s A s s o c i a t i o n , 1 9 4 0 ) p . 80.1.

28

Many a t t e m p t s h a v e b e e n made i n t h e c o n s t r u c t i o n o f r e l i a b l e p r o g n o s t ic t e s t s f o r s te n o g r a p h ic a b i l i t y .

The f o l ­

lo w i n g f a c t o r s h a v e b e e n e x p l o r e d b y many t e a c h e r s and e d u c a ­ t o r s who a r e i n t e r e s t e d in g ,

s y m b o ls ,

i n t h i s p r o b le m : m o to r r e a c t i o n ,

s p e e d o f w r i t i n g , m em ory, I .

f o r e i g n la n g u a g e m a r k s, s c h o l a s t i c

Q ,., E n g l i s h m a r k s,

s ta n d in g , m o t i l i t y , w i l l -

te m p e r a m e n t, an d c l e r i c a l a t t i t u d e . " t i o n s o f s te n o g r a p h ic

s p e ll­

1

H o w e v er , t h e

c o r r e la ­

a b i l i t y w ith t h e s e s t u d i e s have b een t o o

lo w t o b e v a l u a b l e a s a g u id a n c e t e c h n i c a s t h e y a r e o f a m u ltitu d e o f o th e r f a c t o r s in v o lv e d .

ju st

one

A good p r o g n o s tic

t e s t i v i l l h a v e t o b e w e ig h t e d a c c o r d in g t o t h e v a r i o u s a b i l i ­ tie s , in g ,

and w i l l h a v e t o sp eed o f w r it in g ,

in c lu d e

"m otor r e a c t i o n , s p e e d o f r e a d ­

a b ility to s p e ll,

and u s e w o r d s , r e t e n t i v e n e s s

a b ility

to r e c o g n iz e

o f m em ory, r e a d i n e s s w i t h w h ic h

s y m b o ls c a n b e u s e d ," ^ a s w e l l a s " g e n e r a l i n t e l l i g e n c e t e s t , an a c h ie v e m e n t t e s t ,

an E n g l i s h u s a g e t e s t ,

and a m e c h a n i c a l - a p t i t u d e t e s t . " i n c l u d e v a r io u s t r a i t s t r i b u t e s o f h e a r in g ,

3

a c le r ic a l t e s t ,

B l a c k s t o n e w o u ld a l s o

and a t t i t u d e s

as w e ll as p h y s ic a l a t ­

s i g h t , and q u ic k r e a c t i o n .

1 P a u l L. T u r s e ,

o jd

.

c it .,

pp. 3 0 8 -3 0 9 .

2 F ra n k C. P h i l l i p s , " A b i l i t y G ro u p in g A s A F a c t o r o f G u id a n ce i n C u r r ic u lu m S e l e c t i o n . " (New Y ork : F o u r t e e n t h Y e a r b o o k o f t h e E a s t e r n C o m m ercia l T e a c h e r s As 00 c l a t I o il, 1 9 4 1 ) p . 297. rz

Loc.

C lt.

29 j 'H

As i n t e l l i g e n c e ©f t h e s e

s k i l l s and f a c t o r s , many h a v e a ssu m ed t h a t a r g o o d

in te llig e n c e tic

i s v e r y im p o r ta n t i n r e l a t i o n t o a l l

p u rp oses.

t e s t w o u ld b e s u f f i c i e n t l y r e l i a b l e f o r 1p r o g n o s ­ T h is p r o c e d u r e i s

u s e d b y t h e New Y ork S c h o o l

S y s te m a lo n g w i t h v a r i o u s o t h e r r e q u i r e m e n t s ; 1)

O n ly p u p i l s w i t h I . Q. ’ s o f 9 0 o r a b o v e , o r who had an a v e r a g e c f 75 p e r c e n t or m ore i n t h e p r e v i o u s t e r m ’ s w ork i n u n r e p e a t e d s u b ­ j e c t s may e l e c t s t e n o g r a p h y .

2)

P u p i l s i n t h e f i r s t t e r m who h a v e n o t a t t a i n e d a f i n a l r a t i n g o f m ore t h a n 60 p e r c e n t f o r t h e te r m w i l l n o t b e p e r m i t t e d t o c o n t i n u e th e su b je c t.

3)

P u p i l s i n t h e s e c o n d te r m m u st r e c e i v e a f i n a l r a t i n g o f 7 5 p e r c e n t or h i g h e r i n o r d e r t o b e p e r m itte d t o c o n tin u e t h e s u b j e c t .

4)

P r o v i s i o n s h o u ld b e made w h e r e b y c a p a b le s t u ­ d e n t s may r a i s e t h e i r s p e e d a b o v e t h e p r e s e n t secon d y ea r l e v e l s .

5)

R e a s o n a b le r e g u l a t i o n s , m u s t b e made f o r t h e c o n tr o l o f e x c e p tio n s .

P a v a n made a s t u d y o f t h e I . fo r

su ccess.

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Q. w h ic h w as n e c e s s a r y

2 3 0 c o m m e r c ia l g r a d u a t e s o f P h i l a ­

d e l p h i a who w e r e s u c c e s s f u l l y e m p lo y e d a s s t e n o g r a p h e r s and fo u n d t h a t t h e y h a d a m e d ia n X. Q,. o f 1 1 2 . 5 . t h a t an I .

R ig g s c o n c lu d e d p Q. o f 1 0 0 w a s n e c e s s a r y t o l e a r n s h o r t h a n d .

1 R a lp h W. H a l l e r , o p . c i t . , S P a u l L. T u r s e , o p . c i t . ,

p . 165.

p . 305.

O th e r s t u d i e s h a v e fo u n d t h e i n t e l l i g e n c e

r e q u ir e m e n t t o b e

h ig h e r .

S t u d i e s o f c o r r e l a t i o n s o f I . Q,. and s h o r th a n d 1 a c h ie v e m e n t v a r y fr o m .1 8 t o . 5 4 . C o n s e q u e n t ly , t h e r e is - a g r e a t d is a g r e e m e n t h e r e a s i n o t h e r p r o b le m s r e l a t i v e .to s t e n -

nograph y, but a t l e a s t i t lig e n c e I. ic

is n ecessa ry to

Q. i s

is

u s u a l l y a ssu m ed t h a t n o r m a l i n t e l ­

l e a r n s h o r t h a n d and p o s s i b l y a h i g h e r

e s s e n t i a l f o r s u c c e s s f u l a c c o m p lis h m e n t i n s t e n o g r a p h ­

and s e c r e t a r i a l w o rk .

a c c o r d in g to

P h illip s

s t a t e s t h a t a b i l i t y g r o u p in g

i n t e l l i g e n c e w i l l c a u se a " n o tic e a b le d e c r e a s e in

th e p e r c e n ta g e o f f a i lu r e s ;

it

s h o u ld b e p o s s i b l e t o r a i s e

th e

s t a n d a r d s i n s u c h c o u r s e s and s t i l l lo w e r t h e num ber o f f a i l ­ u r e s " w hen t h i s p r o c e d u r e i s

a d o p ted .

G r a d u a te s w i l l b e a b l e

t o m e e t t h e s e h i g h e r s t a n d a r d s and w i l l do m ore s a t i s f a c t o r y and m ore i n t e n s i v e w o r k . A m u l t i t u d e o f p r o b le m s h a v e b e e n c o n s i d e r e d b y b o t h t e a c h e r s and e m p lo y e r s i n a n e f f o r t t o e l i m i n a t e th e m . te a c h e r s lik e to b e lie v e i t

or n o t , t h e s t a n d a r d s w h ic h t h e y

o f t e n s e t a r e n o t t h e sam e a s t h o s e o f t h e e m p lo y e r s . ste n o g r a p h er r e a c h e s th e r e a l t e s t i n t h e e m p lo y e r ’ s o f f i c e ,

it

W h eth er

As th e

o f s t e n o g r a p h i c c o m p e te n c y

se e m s t h a t t h e p r o b le m s o f s t e : - ~

n o g r a p h e r s a s c o n s i d e r e d b y e m p lo y e r s a r e w o r th y o f c o n s i d e r -

P a u l L. T u rse, o £ . c i t . , 2 F ra n k C* P h i l l i p s ,

p . 306.

op* c i t .,

p . 300.

a t io n *

B u s i n e s s m en e n u m e r a te t h e p r o b le m s a s f o l l o w s :

fa ilu r e

to g e t d ic t a t io n ,

i n a b i l i t y t o r e a d s h o r th a n d n o t e s ,

f a i l u r e t o g e t t h e m e a n in g o f t h e d i c t a t i o n , l a c k o f s p e e d i n t r a n s c r i p t i o n , t o o p l e n t i f u l p u n c t u a t i o n , p o o r s p e l l i n g , un­ tid y le t t e r s , sen t

l a c k o f c a r e i n c h e c k in g d e t a i l s .

s u c h p r o b le m s a s t h o s e

T h ese p r e ­

o f p e n m a n s h ip , r e a d i n g , E n g l i s h ,

s p e l l in g , t r a n s c r ip t io n , c o n c e n tr a tio n , p r e c is io n , s e l f - c o n ­ tr o l,

c le a r l o g i c a l t h in k in g , v o c a b u la r y , n e a t n e s s , a c c u r a c y ,

and g o o d b u s i n e s s p r o c e d u r e . A s t u d y o f t h e s e p r o b le m s r e v e a l s t h a t h e a r in g m ig h t be a la r g e f a c t o r ,

a s many o f th em a r e d e f i n i t e l y r e l a t e d

t h e h e a r in g p r o c e s s .

A sta n d a r d o f h e a r in g i s ,

a c h a l l e n g e t o p r o f e s s i o n s i n m any f i e l d s , r e c t c h a lle n g e t o b u s in e s s e d u c a to r s . i n d i v i d u a l s d u r in g t h e g i v e th e m f o r e s i g h t

to

th e r e fo r e ,

but i t

The aim i s

is

a d i­

t o h e lp

p r o c e s s o f f o r m a l e d u c a t i o n , and t o

a b o u t l a t e r e m p lo y m e n t.

o f h e a r in g w i l l h e l p a s t u d e n t t o e n g a g e i n

T h u s, a sta n d a r d a m e a n in g f u l o c ­

c u p a t i o n , o n e i n w h ic h h e m ig h t g r o w , p r o g r e s s and b e h a p p y . The a im o f s e t t i n g up a s t a n d a r d o f h e a r i n g i n raphy is

a n o u tg r o w th o f e x i s t i n g

ste n o g ­

c o n d itio n s , f o r a t th e

p r e s e n t t i m e , v a r i o u s m e th o d s o f i n j u s t i c e a r e u s e d i n t h e e l i m i n a t i o n o f u n d e s i r a b l e s t u d e n t s fr o m t h i s o f t h e s e m e th o d s i s

su b je c t.

One

g i v e n b y a v e r y e x p e r i e n c e d and r e c o g ­

n iz e d te a c h e r in th e f i e l d .

She s a y s ,

" E x p ec t t o d r o p o u t

32 a t t h e end o f e a c h s e m e s t e r p u p i l s

do n o t g i v e p r o m is e o f i r e a c h in g r e a s o n a b l e s t a n d a r d s o f p r o f i c i e n c y . " T h ese s t u ­ d e n t s m ig h t b e d r o p p e d o u t ,

but b eca u se of t h e ir k een i n t e r e s t

i n t h e s u b j e c t , t h e y may p u r s u e i t lic

a t a l a t e r d a te in th e pub­

s c h o o ls or in p r iv a te b u s in e s s s c h o o ls .

T h e r e i s no e x ­

p l a n a t i o n g i v e n c o n c e r n in g g u i d in g th em o u t , o r t e l l i n g

th em

why t h e y w i l l l i k e l y b e u n s u c c e s s f u l a s s t e n o g r a p h i c s t u d e n t s . T h e s e u n s u c c e s s f u l s t u d e n t s a r e t o b e a n t i c i p a t e d an d e l i m i ­ nated s o t h a t t h e y w i l l n o t b e a l i a b i l i t y t o t h e t e a c h e r and t h e d e p a r tm e n t whom t h e y r e p r e s e n t . A s t a n d a r d o f h e a r in g i n s t e n o g r a p h y w o u ld h e l p c o u n ­ s e l o r s in g u id in g y o u th s in t o v o c a t io n s i n v h ic h i n t e n s i v e an d a c c u r a t e h e a r i n g i s is

n o t an e s s e n t i a l f a c t o r .

a r e a l n eed to be m et.

One h a s o n l y t o

T h u s, th e r e

l o o k th r o u g h t h e

j o u r n a l s o f b u s i n e s s e d u c a t i o n t o f i n d t h a t t h e r e i s much c o n ­ f u s i o n an d d i s c u s s i o n a s t o why s t u d e n t s a r e f a i l i n g im p o r t a n t s u b j e c t .

One h a s o n l y t o

n a ls t o fin d th a t th e r e i s c h ild r e n s u f f e r in g d e fe c ts;

in t h i s

lo o k i n th e m e d ic a l jo u r ­

a v e r y la r g e p e r c e n ta g e or s c h o o l

fr o m v a r i o u s t y p e s an d d e g r e e s o f h e a r i n g

c o n s e q u e n tly , i t

se e m s o b v io u s t h a t a s h e a r in g i s

1 O liv e J e n s e n , " B u ild in g T r a n s c r i p t i o n A b i l i t i e s . " (W a sh in g to n D . C . : F i f t h ,Y e a r b o o k o f t h e N a t i o n a l C om m ercial T e a c h e r s F ed e r a t i o n , 1 9 5 9 ) p . 2 8 6 .

35 s u c h an e s s e n t i a l f a c t o r i n o a r e d u c a t i o n a l p r o c e s s , and a s s o many s t u d e n t s a r e a f f l i c t e d h e a r in g m ig h t b e o n e o f t h e

w i t h h e a r i n g im p a ir m e n t s , t h a t

ca u ses o f f a ilu r e .

E ven t h o u g h

t h e p e r c e n t a g e o f h a r d - o f - h e a r i n g s t e n o g r a p h ic

s t u d e n t s may

be s l i g h t ,

fr o m t h e o t h e r s

it

is

u rg en t th a t th o s e be s e le c t e d

and t r a i n e d i n t h e v o c a t i o n s i n w h ic h t h e y m ay becom e e f f i ­ c ie n t.

It

is

a ls o

u r g e n t t h a t t h o s e who n e e d p r o p e r m e d i c a l

s e r v i c e s and a d j u s t m e n t s d u e t o h e a r in g im p a ir m e n t b e p r o v i d ­ ed f o r a s s o o n a s p o s s i b l e .

S u ch a p r o c e d u r e w o u ld n o t o n l y

s e r v e im m e d ia te n e e d s , b u t w o u ld s e r v e u l t i m a t e m o t i v e s a s w e ll. I f a u d i o m e t r ic t e s t s w e r e g i v e n s t e n o g r a p h e r s , t h e r e w o u ld b e a p o s s i b i l i t y

o f f i n d i n g t h o s e w h o se h e a r in g w as

m o st a c u t e who w o u ld w a r r a n t t h e

a d v i s a b i l i t y o f su ch t r a i n ­

i n g , and t h e d e f i c i e n c y m ig h t b e c h e c k e d i n t h o s e i n w h ic h im p a ir m e n ts e x i s t e d : New w a y s a r e b e i n g d i s c o v e r e d t o c u r t a i l t h e i n r o a d s m ade b y p r o g r e s s i v e d e a f n e s s w i t h w h ic h u n c o u n te d t h o u s a n d s o f A m e r ic a n s a r e a fflic te d . The m o st w o r t h w h ile c o n t r i b u t i o n s a r e b e i n g made i n o t o l o g y t o w a r d s p r e v e n t i o n o f d e a f n e s s i n c h ild h o o d w hen m o st e a r t r o u b l e s s t a r t ; i n a u d i o m e t r ic t e s t i n g o f h e a r in g t o d e ­ t e r m in e t r e n d s o f h e a r in g l o s s i n p o p u l a t i o n , a s w e l l . a s i n p u b l i c s c h o o l s ; i n a c o u s t i c s , f o r im ­ p ro v ed h e a r in g a id s ; i n e d u c a tin g th e i n d iv id u a l t o m ake u s e o f s m a ll r e s i d u e s o f h e a r i n g l e f t o v e r fr o m h e a r in g t h a t o n c e w as n o r m a l; i n t r a i n ­ i n g e y e s , e a r s , and m ind t o c o o p e r a t e i n t h e

34 b e t t e r u n d e r s t a n d in g o f s p e e c h .* 1" T h ere i s to

a h ig h in c id e n c e o f m i s f i t s i n

im p a ir e d h e a r i n g .

em p loym en t due

Many c a s e s h a v e b e e n c i t e d

to

th e w r it e r

d u r in g t h e s t u d y fr o m v a r i o u s v o c a t i o n s i n w h ic h a h i g h d e ­ g r e e o f h e a r in g i s te lls

e s s e n tia l.

One n i n e t e e n y e a r o l d b o y ?

h is p a th e tic s to r y a s fo llo w s : " A lth o u g h I h a v e h ad a h i g h s c h o o l e d u c a t i o h . a n d t h r e e . y e a r s 1 o f * - e x p e r ie n c e a s a b o o k ­ k e e p e r , I am c o m p e lle d t o w ork f o r t e n d o l l a r s a w e ek on a c c o u n t o f my d e a f n e s s . L a s t " n ig h t 1 w a s t r a n s f e r r e d t o a n o t h e r d e p a r tm e n t t o do ste n o g r a p h y . How a b s u r d J Why I d o n ft h e a r a t a l l w e l l en o u g h t o t a k e d i c t a t i o n . What i s t o b e d o n e? " & S h o u ld o n e h a v e f o l l o w e d t h e h i s t o r y o f t h i s b o y f s

e m p lo y m e n t, o n e w o u ld h a v e p r o b a b ly fo u n d a g r e a t d e a l o f u n e a s i n e s s an d u n h a p p in e s s , f o r e v i d e n t l y t h e e m p lo y e r h im ­ s e l f w a s ig n o r a n t c o n c e r n in g h e a r in g im p a ir m e n t. t e e n y e a r o l d b o y c o u ld fo r e se e u l t i m a t e f a i l u r e "What i s

t o b e d o n e? "

T h is i s t h e

The n i n e ­ and a s k e d ,

q u e s t i o n w h ic h b a f f l e s

e d u c a t o r s v£io o c c a s i o n a l l y f a c e t h e p r o b le m .

H ow ever, t h e y

c la i m t h a t t h e c a s e s a r e so r a r e t h a t t h e p r o b le m i s w o r th t h e i r c o n s i d e r a t i o n .

Y e t, th e y f a i l to

not

r e a liz e t h e ir

^ L o u is e M. N e w s c h u t z , How t o H e lp Y our H e a r i n g , (New Y ork : H a r p e r *and B r o t h e r s P u b l i s h e r s , 1 9 4 0 } p . x v i i i . 2

PP* 6 0 - 6 1 .

o b l i g a t i o n t o t h e " w h o le ” c h i l d an d t o e v e r y c h i l d whom t h e y t e a c h i n p r o v i d i n g them w i t h e d u c a t i o n t o s u i t t h e i r in d iv id u a l n e e d s. S i n c e t h e p r im a r y p u r p o s e o f e d u c a t i o n i s

t o m ee t

i n d i v i d u a l n e e d s , t h e y o u t h who i s h a n d ic a p p e d h a s a r i g h t to

e x p e c t a s much fro m h i s f o r m a l e d u c a t i o n a s h a s a n y o t h e r

s t u d e n t — t h e r i g h t t o be e q u ip p e d s o t h a t h e c a n p r o g r e s s in a v o c a tio n .

I t may n o t b e u n t i l t h e t r a i n i n g i s

b u t a t some tim e o r o t h e r e a c h p e r s o n i s

over,

m e a su r e d i n t h e n e c ­

e s s a r y r e q u ir e m e n t s o f t h e o c c u p a t i o n h e c h o o s e s , an d h e i s e l i m i n a t e d i f h e i s n o t g i v i n g h i s e m p lo y e r s e r v i c e s f o r t h e p r i c e h i s e m p lo y e r p a y s f o r th e m .

s u ffic ie n t

Im p ro v ed e f f i c i e n c y

com es o n l y from im p r o v ed s e l e c t i o n an d im p r o v e d t r a i n i n g o f p e r s o n n e l.

T h is m e a su r e i s n o t o n l y e c o n o m ic a l f o r t h e i n d i ­

v id u a l w ith d e f e c t i v e h e a r in g , b u t a l s o

f o r t h e e c o n o m ic v a l u e

o f s o c ie ty as w e ll. T h er e a r e many t y p e s an d d e g r e e s o f im p a ir m e n t, and t h e r e a r e no tw o p e o p l e w i t h t h e same h e a r i n g a c u i t y e v e n th o u g h t h e y may h a v e t h e same am ount o f h e a r i n g l o s s w i t h e x ­ a c t a u d io g r a m s .

H o w e v er , h a d t h i s c a s e o f im p a ir m e n t b e e n

t h o r o u g h ly s t u d i e d , t h e b o y w o u ld n o t h a v e h a d t o l o s e

tim e and

v o c a t i o n a l t r a i n i n g , an d f a i l u r e m ig h t n o t h a v e f a c e d him a t t h i s e a r ly a g e .

W ould n o t t h i s

o f a sch oo l c lin ic ,

on e c a s e h a v e j u s t i f i e d

th e ex p en se

o r a n a u d io m e t e r f o r t e s t i n g h e a r i n g , t o

36 sa y n o th in g o f th e

s i m i l a r c a s e s w h ic h a r e u s u a l l y fo u n d i n

t h e a v e r a g e s c h o o l?

It

is

im p e r a tiv e t h a t th e d e f e c t b e d i s ­

covered as e a r ly as p o s s ib le .

The d e g r e e o f h e a r in g l o s s i s

a n im p o r ta n t f a c t o r i n v o c a t i o n a l s u c c e s s . o n t h e p e r s o n a l i t y an d a t t i t u d e s o f t h e s id e r a tio n . c a lle d th a t

Much a l s o d e p e n d s

i n d iv id u a l under co n ­

The c h i l d m u st be s t u d i e d b y t h e m eth o d w h ic h i s o f p r o je c tio n in te r p r e ta tio n ,

o r t h e w h o le c h i l d ,

and th e i n t e r r e l a t e d n e s s o r th e c o n t i n u it y o f th e v a r io u s g r o w th p r o c e s s e s #

T h is s t u d y i n c l u d e s c o n s i d e r a t i o n o f cumu­

l a t i v e r e c o r d s , e d u c a t io n a l in fo r m a tio n a v a i l a b l e , p e r s o n a l­ ity ,

and c o n s t a n t f o l l o w - u p s t u d i e s o f a c h ie v e m e n t and p r o g r e s s . The c o u n s e l o r w i l l f i n d t h a t much c a n be a c c o m p lis h e d

by p e r so n a l in te r v ie w

i n w h ic h c o n s i d e r a t i o n b y a n a l y t i c , d i a g ­

n o s t i c , and p r o g n o s t i c t e s t s h a v e b e e n g i v e n c o n c e r n i n g e a c h ca se.

T h is i s w h er e g e n e r a l s c h o l a s t i c

a b ility ,

a c h ie v e m e n t ,

a p t i t u d e s , p e r s o n a l i t y c h a r a c t e r i s t i c s and I n t e r e s t s p l a y an im p o r t a n t p a r t . A fte r

u h orou gh s t u d i e s h a v e b e e n made a l o n g t h e s e l i n e s ,

t h e c o u n s e l o r m u st h e l p t o

o v e rc o m e p e r s o n a l an d s o c i a l m a l­

a d j u s t m e n t s and c r e a t e s e l f - c o n f i d e n c e h a r d -o f-h e a r in g

in th e

in d iv id u a l.

The

i n d i v i d u a l m u st h a v e o c c u p a t i o n s i n w h ic h h e

c a n w ork w it h o u t d a n g e r o f i n j u r y , i n w h ic h s p e e c h and h e a r i n g do n o t p l a y im p o r t a n t p a r t s , o n e i n w h ic h h e c a n a d a p t h i m s e l f , w here t h e r e

is

little

n o i s e , n o d a m p n ess o r v a r y in g t e m p e r -

37 a t u r e s , an d o n e i n w hich, h e i s A lth o u g h i n t e r e s t

is

in te r e s te d .

v e r y im p o r t a n t i n c h o o s i n g a v o ­

c a t i o n , e x p e r im e n t s o f W it t y an d o t h e r s t e n d t o

d is a g r e e

w i t h t h e common a s s u m p t io n t h a t i n t e r e s t and a b i l i t y in hand. is

g o han d

Y o u th v o c a t i o n a l c h o i c e s a r e m ore oB&angeable t h a n

p erh a p s any o th e r c h a r a c t e r i s t i c

o f h i s m a k e -u p .

U s u a lly

i n t e r e s t d o e s n o t becom e p e rm a n en t u n t i l a f t e r v o c a t i o n a l c h o i c e h a s b e e n m ad e.

I t may b e c o n d i t i o n e d , r e d i r e c t e d , and

r e t r a i n e d , and e v e n s t a b i l i z e d b e e n d e t e r m i n e d .1

a f t e r th e v o c a t io n a l c h o ic e h a s

T h is p s y c h o lo g y i s

new an d s h o u ld mean a

g r e a t d e a l t o t h e c o u n s e l o r w h o se d u t y i s t o g u i d e s t u d e n b s i n t o v o c a t i o n s , p a r t i c u l a r l y t h o s e h a n d ic a p p e d s t u d e n t s who h ave n o t begun t o

r e a liz e th e ir

lim ita tio n s .

E a r ly i n l i f e

h a n d ic a p p e d s t u d e n t s m ay b e c o n d i t i o n e d i n t o v o c a t i o n s i n w h ic h t h e y a r e n o t i n t e r e s t e d , b u t i n w h ic h t h e y may becom e i n t e r e s t e d and a d j u s t e d t h r o u g h p r o p e r g u id a n c e and d i r e c t i o n . What a r e t h e g e n e r a l o b j e c t i v e s b y w h ic h t h e p r o b le m o f a s t a n d a r d o f h e a r in g i n e d u c a t i o n m ay b e s u r v e y e d ? are n a tu r e ,

s o c i a l e f f i c i e n c y , an d c u l t u r e .

in d iv id u a l c a p a c it ie s , m e n t.

T h ese

H a tu r e g i v e s t h e

d i s p o s i t i o n s and l i m i t a t i o n s o f d e v e l o p ­

A c h i l d b o r n i n t o t h e w o r ld w i t h a h e a r in g im p a ir m e n t

**■ S a l v a t o r i G. D i M ic h a e l, " U sin g I n t e r e s t s a s t h e B a s is o f V o c a tio n a l C h o ic e ,” V o c a tio n s , 2 0 ;2 7 0 -2 7 5 , J a n u a ry , 1942.

38 or so a f f l i c t e d

e a r ly in l i f e ,

h a s no c o n t r o l o v e r th e c i r ­

c u m s t a n c e s , b u t may b e p r o p e r l y c a r e d f o r b y s u r g e r y , and t h e d e f e c t may b e e l i m i n a t e d , o r t h e e x t e n t o f t h e im p a ir m e n t d ecrea sed .

H o w e v e r , t h e n a t u r e o f t h e im p a ir m e n t h e l p s t o

r e g u l a t e and d e t e r m in e t h e l i f e

p a tte r n o f condu ct a s w e ll

a s th e

in d iv id u a l.

s o c ia l e f f ic ie n c y o f th e

The c o u n s e l o r

m u st d i r e c t an i n d i v i d u a l ’ s c a p a c i t i e s t o t h e b e s t p o s s i b l e u s e , f o r c a p a c i t i e s becom e c o n d i t i o n e d b y t h e u s e t o w h ic h th e y a re p u t. T h o se who a r e a f f l i c t e d w i t h h e a r in g im p a ir m e n ts m u st n ot be l e f t

to

c h a n c e o r s p o n t a n e o u s g r o w th o r made t o

fit

i n t o t h e e d u c a t i o n a l p ro g ra m o f t h a t o f t h e a v e r a g e e h i l d . T he h a r d - o f - h e a r i n g c h i l d as e a r ly as p o s s ib le s e le c te d

and h i s e n v ir o n m e n t s h o u ld b e c a r e f u l l y

s o t h a t h i s s t r o n g p o i n t s w o u ld c o m p e n sa te f o r h i s

w eak n esses*

T h e s e n a t u r a l t e n d e n c i e s w h ic h a r e b e n e f i c i a l

t o a h a n d ic a p p e d c h i l d b le .

s h o u ld b e in fo r m e d o f h i s h a n d ic a p

H is i n t e r e s t

s h o u ld b e e n c o u r a g e d a s much a s p o s s i ­

i n t h o s e e n v ir o n m e n t a l f a c t o r s w h ic h r e ­

q u ir e a h ig h d e g r e e o f t r a i n in g

and w h ic h w o u ld o n l y make t h e

c h i l d c o n s c i o u s o f h i s d e f e c t s h o u ld b e d i s c o u r a g e d .

T h is

a t t i t u d e w as m a n i f e s t e d by~~the v a r i o u s p e r s o n n e l d i r e c t o r s o f i n d u s t r y a t t h e t im e o f t h e

s t u d y a s h a n d ic a p p e d i n d i v i d u a l s

w e r e p l a c e d i n t y p e s o f i n d u s t r y w h ere t h e v a r i o u s d e f e c t s w ere s l i g h t l y n o t ic e a b le

and w o u ld o n l y s l i g h t l y

lim it th e

39 p r o d u c tio n o f th e

in d iv id u a l*

W ith p r o p e r g u i d a n c e , t h e h e a r in g d e f i c i e n c y e a r l y in l i f e o f ste n o g r a p h y i f l e c t tr a in in g

c h i l d who l e a r n s o f h i s w o u ld n o t a t t e m p t t h e

he w e r e p r o p e r l y c o u n s e le d .

stu d y

He w o u ld s e ­

i n t h o s e o c c u p a t i o n s i n w h ic h h e c o u ld becom e

s o c ia lly e f f ic ie n t ,

i n d u s t r i a l l y c o m p e t e n t , and a g o o d c i t i ­

z e n who w a s h a p p y a n d c o n t e n t i n h i s v o c a t i o n a l c h o i c e . T h u s , h e w o u ld b e a b l e t o r e a l i z e t h e b r o a d m a jo r o b j e c t i v e s d e s i r e d b y a l l h a v in g made h i s own v o c a t i o n a l c h o i c e and s o ­ c i a l a d ju s tm e n t, w ith a m a s te r y o f enough s i c i l l s so t h a t he c o u l d co m m u n ica te and a d a p t h i m s e l f t o h i s

e n v ir o n m e n t emo­

t i o n a l l y and m e n t a l l y , w i t h a s o c i a l h e r i t a g e and p r o p e r s e n s e o f d ir e c tio n . C o n s e q u e n t ly , i f e a r ly d e te c tio n

t h e r e i s no p r o v i s i o n made f o r t h e

o f h e a r in g im p a ir m e n t i n t h e e a r l y y e a r s o f

a c h i l d ’ s e d u c a tio n , b e fo r e he b e g in s to s p e c i a l i z e ' in th e fie ld

o f s t e n o g r a p h y , h e s h o u ld b e t h o r o u g h l y e x a m in ed f o r

h e a r i n g im p a irm e n t e a r l y i n t h e s e r io u s or p r o g r e s s iv e

co u rse so th a t

i f he h a s a

im p a irm e n t h e c o u ld b e g u id e d i n t o

a - v o c a t io n i n w h ic h h e a r in g w e r e n o t

s o im p o r ta n t , and a t

t h e sam e t im e g i v e n p r o p e r m e d i c a l - t r e a t m e n t f o r th e p a ir m e n t .

B o th m e a s u r e s a r e v i t a l l y

tu r e o f th e in d iv id u a l.

The s t u d e n t

im ­

im p o r ta n t t o t h e f u ­ s h o w in g a h e a r in g im ­

p a ir m e n t s h o u ld b e c a r e f u l l y s t u d i e d , t o l d

o f th e n a tu r e

40 o f h i s I m p a ir m e n t, and h e l p f u l c o u n s e l i n g g i v e n i n o c c u p a ­ t i o n a l c h o i c e w h ic h m ig h t b e b e t t e r s u i t e d t o h i s n a t u r a l c a p a c ity . SUMMARY.

S i n c e t h e p r im a r y a im o f t e a c h i n g

w as f o r t h e t r a i n i n g o f s t u d e n t s w i t h s t e n o g r a p h i c

sh o rth a n d s h ills

p r e p a r a t o r y t o t h e i r v o c a t i o n a l a d j u s t m e n t , i t w as c o n s i d e r e d n ecessa ry to

s t u d y som e o f t h e p r e v a i l i n g p r a c t i c e s o f t h e

s te n o g r a p h ic d e p a r tm en ts i n th e s e l e c t i o n m e th o d s u s e d b y t h e

o f stu d e n ts.

v a r io u s s c h o o ls d i f f e r e d

The

c o n s id e r a b ly .

Some s t e n o g r a p h i c d e p a r t m e n t s w e r e f a r t o o l e n i e n t i n p e r m i t ­ t i n g a l l t h o s e d e s i r i n g t o t a k e s h o r th a n d t o : p u r s u e t h e ' s t u d y and o t h e r m e th o d s o f d i s c r i m i n a t i o n w erd u n j u s t a s i n s t r u c t o r s d id n o t c o u n s e l s t u d e n t s a s to t h e i r

s h o r t c o m in g s , b u t in f o r m e d

th em o f t h e i r i n a b i l i t y t o

s u b j e c t and o f t h e f a c t

stu d y th e

t h a t t h e y w o u ld n o t b e p e r m i t t e d t o fa ilin g

th e m .

c o n tin u e th e stu d y by

A lth o u g h a g o o d p r o g n o s t i c t e s t w as c o n s i d e r e d ,

t h e i d e a l c r i t e r i o n , a r e l i a b l e one had n o t b e e n c o n s t r u c t e d , and i n t e l l i g e n c e t e s t s in a l l or s e l e c t e d

and c e r t a i n minimum g r a d e r e q u ir e m e n t s

s u b j e c t s w ere c o n s id e r e d a s th e b e s t

m e th o d s o f s e l e c t i o n b e i n g u s e d . The aim o f a s t a n d a r d o f h e a r i n g i n s t e n o g r a p h y w a s t o h e lp

s t u d e n t s h a v in g d e f e c t i v e ; h e a r i n g r e a l i z e why t h e y

w o u ld p r o b a b ly b e u n s u c c e s s f u l i n an o c c u p a t i o n w h ere a c u t e h e a r i n g o f s p e e c h w as e s s e n t i a l .

E ven th o u g h t h e y m ig h t h e a r

w e l l en o u g h a t t h e b e g i n n i n g o f t h e

stu d y t o p a s s in

t h e c o u r s e ,,.- o f t e n t h e p r o g r e s s i v e t e n d e n c i e s and t h e n a t u r e o f t h e d e f e c t w o u ld n o t j u s t i f y

t h e i r f u t u r e s u c c e s s i n th e

o c c u p a t i o n a s h e a r i n g im p a ir m e n t u s u a l l y i n c r e a s e s w i t h a g e . H ow ever, i f

o c c u p a tio n a l c h o ic e

i s made s o o n e n o u g h , t h e

c h ild

w i t h a h e a r i n g im p a ir m e n t w o u ld h a v e an o p p o r t u n i t y e q u a l t o t h a t o f h i s c l a s s m a t e s f o r t h e t r a i n i n g i n an o c c u p a t i o n i n w h ic h he m ig h t becom e a d j u s t e d and h i s c a p a c i t i e s c o n d i t i o n e d i n l i n e w ith h i s v o c a t io n a l s e l e c t i o n e a r l y i n l i f e su ch tr a in in g

c o u ld b e b e s t l e a r n e d .

an o p p o r tu n ity t o tiv e

s e le c t

when

T h u s , h e w o u ld h a v e

an o c c u p a tio n s u it a b le

to h is na­

a b i l i t i e s w n ic h m ig h t make him in d e p e n d e n t a n a a b l e t o

e n jo y l i f e

a b u n d a n t ly .

42 C h a p te r 2 THE PSYCHOLOGY AND PHYSIOLOGY OF HEARING

* B i o l o g i s t s t e l l u s t h a t h e a r in g i s p h y lo g e n e t i c a l l y t h e l a t e s t and m o st e l a b o r a t e l y d e ­ v e lo p e d s p e c i a l s e n s e . C e r t a i n l y no on e ca n v i e w t h e c o m p l e x i t y o f i t s a n a t o m ic a l s t r u c t u r e w i t h o u t b e i n g p r o f o u n d l y i m p r e s s e d , and a s t o i t s f u n c t i o n , w hen we c o n s i d e r i t s s e n s i t i v e n e s s t o so u n d s (e v e n to th e m fiim te s im a l f a i n t n e s s o f 1 /1 0 0 0 o f a dyne e q u iv a le n t t o o n e - b i l l i o n t h o f a t m o s p h e r ic p r e s s u r e ) t o g e t h e r w it h t h e e x t r a ­ o r d i n a r y r a n g e o f i n t e n s i t i e s t o w h ic h i t ca n r e s p o n d (u p t o o n e b i l l i o n t i m e s t h e t h r e s h o l d v a l u e ) , when we c o n s i d e r t h e num ber and d i v e r s i t y o f i t s s e n s e q u a l i t i e s , we f e e l t h a t we may r i g h t l y c l a i m t h a t h e r e i n d e e d i s a consum m ate w ork o f n a t u r e , n o t s u r p a s s e d b y a n y consum m ate w ork o f a r t . _ As h e a r in g i s

o n e o f t h e tw o m o st im p o r ta n t

sen ses o f

m an, and i n a s much a s t h e w h o le m e n t a l p i c t u r e o f t h e w o r ld m u st b e c o n v e y e d t o t h e m in d b y t h e s e n s a t i o n s o f s i g h t a n d h e a r in g ,

it

i s n e c e s s a r y t h a t t h e p s y c h o l o g i c a l and p h y s i o ­

l o g i c a l p r o c e s s e s b e e x a m in e d fr o m t im e t o t im e i n o r d e r t o s t u d y th em and d i s c o v e r new w a y s and m ea n s o f l e n g t h e n i n g and i n c r e a s i n g t h e i r e f f i c i e n c y . s i o n s b ecom e d e f e c t i v e

As t h e s e

s e n s o r y im p r e s ­

so a l s o d o e s t h e m e n t a l and p h y s i c a l

c o n d i t i o n o f t h e i n d i v i d u a l becom e a f f e c t e d . o f e x a m in in g t h e f u n c t i o n o f h e a r in g t h a t

it

It

is

b y m eans

is p o s s ib le to

W a lt e r A . W e l l s , "The D a n g er t o H e a r in g A p p a r a tu s i n M odern W a r f a r e , "E y e , E a r , N o se and T h r o a t M o n t h ly , pp. 4 5 -5 0 , F eb ru ary, 1941.

43 e s t i m a t e t h e a p p r o x im a te p e r c e n t a g e o f l o s s o f t h a t f u n c t i o n . I t h a s n o t y e t b e e n d i s c o v e r e d how much t h e human m ec h a n ism is

c a p a b le o f h e a r i n g , p a r t i c u l a r l y i n t h e m a t t e r o f s p e e c h ,

b u t i t h a s b e e n f a i r l y w e l l d e te r m in e d w h at i t

cannot h e a r .

The t h r e e a s p e c t s o f t h e p e r c e p t u a l p r o c e s s o f h e a r in g are th e s tim u lu s , th e n e u r a l a c t i v i t y ,

and t h e

resp o n se.

f i n a l fo rm o f t h e a u d i t o r y r e s p o n s e i s

c o n d itio n e d by th e

The

m id d le e a r , t h e

c o c h l e a , and t h e a u d i t o r y n e r v e .

A d eq u a te

d iffe r e n tia tio n

o f th e a s p e c t s o f h e a r ih g , e s p e c i a l l y o f f r e ­

q u e n c y and i n t e n s i t y m u st c o n s t i t u t e t h e p e r c e p t u a l p r o c e s s o f h e a r in g .

The d i s c r i m i n a t o r y r e a c t i o n s t o p i t c h , l o u d n e s s ,

v o lu m e , and d e n s i t y a r e b a s e d on a c o m b in a tio n o f tw o v a r i ­ a b le s o f th e o f r e a c tio n .

s t i m u l u s w h ic h make p o s s i b l e f o u r d i f f e r e n t t y p e s The a t t i t u d e w h ic h on e t a k e s to w a r d s t h e s e

s a t i o n s d e t e r m in e t h e

c h a r a c te r o f d if f e r e n t ia t io n

m uch a s d o e s t h e s t i m u l u s i t s e l f .

sen ­

ju st as

I t fo llo w s th a t th e

lis ­

te n e r c o n s t i t u t e s a p a r t o f th e s tim u lu s p a t t e r n . The e a r w i t h i t s m any d e l i c a t e i s t h e m ec h a n ism o f h e a r i n g .d e t e r m in e d b y t h e l e a s t n ecessa ry to e x c ite

and c o m p l ic a t e d p a r t s

The s e n s i t i v i t y

o f th e e a r i s

am ount o f e n e r g y o r so u n d p r e s s u r e

or s t im u la t e a s e n s a t io n o f h e a r in g .

S t a n l e y S . S t e v e n s and H . D a v i s , H e a r i n g , I t s P s y c h o l o g y and P h y s i o l o g y , (New Y ork : J o h n W ile y and S o n s , I n c ., 1 9 3 8 ), p . 436.

T h is s e n s i t i v e n e s s o r t h r e s h o l d v a l u e v a r i e s w i t h t h e a g e o f th e o b serv er^ ,

i n d i v i d u a l d i f f e r e n c e s , t h e num ber o f e a r s

t e s t e d , th e ty p e o f th e

so u n d f i e l d ,

t h e o b s e r v e r w ith r e s p e c t t o th e it

and t h e

o r ie n ta tio n o f

so u n d f i e l d , 1

The u p p e r l i m ­

o f h e a r in g c o r r e s p o n d s t o t h e l o u d n e s s l e v e l ,

lim it i s

c a lle d th e th r e s h o ld of f e e l i n g

l e a s t th a t one can h e a r . lie s

th e th r e s h o ld

as it

t h e lo w e r

i n d i c a t e s th e

B e tw e e n r h e s e u p p e r and lo w e r l i m i t s

o f a u d i b i l i t y w h ic h i n d i c a t e s t h e

h e a r in g f o r any g iv e n e a r .

range of

T he e a r s a r e m o st e f f i c i e n t i n

y o u th , b u t w ith in c r e a s in g a g e , t h e r e i s h e a r in g a c u i t y due t o d i s e a s e ,

a r e la tiv e lo s s o f

o r g a n ic d is t u r b a n c e s , ab ru p t

n o i s e s , d r u g s , and n u m ero u s o t h e r c a u s e s . come i n t h e fo r m o f so u n d w a v e s .

The a u d i b l e s o u n d s

A d i f f i c u l t p r o b le m o f h e a r i n g

i s t h a t o f t r a c i n g t h e e f f e c t o f t h e s e v a r i o u s s o u n d -w a v e s on t h e human o r g a n is m . p o s s ib le to

Many r e c e n t d e v e lo p m e n t s h a v e .made t h i s

som e e x t e n t .

W ith t h e

in v e n t io n o f t h e th e r m io n ic

t u b e and e l e c t r i c a l m e c h a n i c s , s c i e n t i s t s h a v e b e e n a b l e t o g e n e r a t e and m e a s u r e t h e s e s o u n d -w a v e s o f m any f o r m s .

The

e l e c t r i c w ave m ay b e s t u d i e d b y t h e sw e e p c i r c u i t w h i l e so u n d i n t e n s i t y i s m e a s u r e d b y a c a l i b r a t e d m ic r o p h o n e .

The so u n d

w a v e s may b e b r o k e n i n t o t h e i r s i m p le h a r m o n ic m o t io n s and a n a l y z e d b y a s e r i e s o f r e s o n a t o r s and e l e c t r i c a l w ave a n a l y z e r s .

1 Ibid. p. 42.

45 T he s o u n d -w a v e s a r e v i b r a t o r y m o t io n s w h ic h a r e a b l e to

a r o u s e a u d i t o r y s e n s a t i o n s when t h e y a r e co m m u n ic a te d t o

t h e a u d i t o r y m e c h a n ism .

T h is m ec h a n ism may b e s t i m u l a t e d b y

t h e s o u n d -w a v e s i n t h e a i r , th e b on es o f th e

sJfcu ll.

i n t h e w a t e r , or d i r e c t l y t h r o u g h

The s o u n d -w a v e s may s t i m u l a t e h e a r ­

i n g a s t h e y p a s s fr o m o n e p a r t o f t h e m edium t o t h e o t h e r u n t il th e

e n tir e

s tim u la tio n s e t s

a u d i t o r y m edium i s

s tim u la te d .

up a w ave o f d i s t u r b a n c e .

T h is g r a d u a l

"The l e n g t h o f a

so u n d -w a v e i s t h e d i s t a n c e t r a v e r s e d b y t h e so u n d i n t h e r e ­ q u ir e d t im e t o

c o m p le t e o n e c y c l e .

The w a v e - l e n g t h i s

t o t h e v e l o c i t y o f t h e w ave d i v i d e d b y i t s Sound, th e n , i s and i n t e n s i t y p itc h ,

as i t s

is

f r e q u e n c y ."

a s t im u lu s to h e a r in g w ith fr e q u e n c y

d im e n s io n s .

O th e r a s p e c t s o f so u n d a r e

l o u d n e s s , v o lu m e , and d e n s i t y .

a so u n d w a v e , i t

equal

I n o r d e r to

d e t e r m in e

n e c e s s a r y t o icnow t h e s e tw o im p o r ta n t d i ­

m e n s io n s .

T he p h y s i c a l q u a l i t i e s o f h e a r in g a r e p i t c h and

lo u d n e s s .

In ord er to

e s t i m a t e t h e l o u d n e s s o f a s o u n d , one

m u st f i n d o u t t h e e f f e c t o f t h e so u n d on t h e human o r g a n is m . P itc h

is

d e t e r m in e d b y t h e o b s e r v e r , and i s m ore or l e s s a

p s y c h o lo g ic a l a t t r i b u t e , f o r p it c h v a r ie s w ith in d iv id u a ls , and i t may v a r y w i t h t h e

sam e i n d i v i d u a l fro m d a y t o d a y .

"For lo w t o n e s , t h e p i t c h d e c r e a s e s w i t h i n t e n s i t y ,

Ibid, p. 8

b u t, fo r

46 h ig h t o n e s , th e p i t c h in c r e a s e s w ith i n t e n s i t y . ”

The

p i t c h f o r im p u re t o n e s i s m ore s t a b l e t h a n f o r p u r e t o n e s . T he l o u d n e s s o f t h e so u n d -w a v e d e p e n d s o n t h e fo r m and t h e a m p lit u d e o f t h e w a v e .

B y f r e q u e n c y i s m ea n t t h e num ber

o f tim e s p er seco n d t h a t a v ib r a t in g p a r t i c l e

c o m p le t e s a

c y c l e w h ic h i s tw o s i n g l e v i b r a t i o n s o r o n e d o u b le v i b r a t i o n . P i t c h an d l o u d n e s s a r e p h y s i c a l q u a l i t i e s , b u t f r e q u e n c y and i n t e n s i t y a r e a s p e c t s o f s o u n d d e p e n d in g on f o r c e d v i b r a t i o n s . T h ese v ib r a t io n s a r e m easu red b y t h e u se o f in s tr u m e n t s . O th e r p h y s i c a l a s p e c t s b e s i d e s f r e q u e n c y and i n t e n s i t y a r e en ergy, v e lo c ity ,

and p h a s e .

The l o g a r i t h m i c m ea su r em e n t o f t h e d e c i b e l i s

u sed t o

e x p r e s s , t h e l e n g t h o f t h e s e n s a t i o n a t t h e en d o f t h e so u n d w ith t h a t a t t h e b e g in n in g . e le c tr ic

W ith t h e a p p l i c a t i o n o f t h e

c u r r e n t u s e d i n d e v i s i n g t h e a u d io m e t e r , t h e m e a s u r e ­

m en t o f f r e q u e n c y h a s b ecom e t h e m o st c o n s t a n t a t t r i b u t e so u n d .

of

The s im p le h a r m o n ic m o t io n s a d d ed t o g e t h e r fo r m com ­

p le x m o tio n s . in t o .t h e ir

The c o m p le x p e r i o d i c m o t io n s may b e a n a ly z e d

s i m p le h a r m o n ic c o m p o n e n ts i n a c c o r d a n c e w i t h

f f o u r i e r 1s th e o r u m w b ic h i s

t h a t a p e r i o d i c m o t io n o f a f u n d a ­

m e n t a l f r e q u e n c y may b e r e d u c e d t o s i m p l e h a rm o n ic m o t io n s o f 2 s u i t a b l e a m p l i t u d e s , p h a s e s , and f r e q u e n c i e s . 1 I b id , p . 7 2 . 2

p

* 19*

47 It

i s w e l l known t h a t t h e p i t c h

a l t e r e d w i t h o u t c h a n g in g i t s

f r e q u e n c y a s w e l l a s c a n a lo u d

t o n e b e v a r i e d w it h o u t c h a n g in g i t s tio n

o f a to n e i s

I f th e its

so u n d i s

in te n s ity .

e a s ily

very s h o r t,

fa m ilia r , i t s

o f a p u r e t o n e can b e

it

in te n s ity .

is

I f th e

d u ra­

s p o k e n o f a s an i m p u ls e .

d i s t a n c e , c a n be d e t e r m in e d by

T he m ore c o m p le x t h e t o n e o r n o i s e , th e m ore

i t m ay be l o o a t e d .

In order to

lo c a te

so u n d , p e o p le

a r e i n f l u e n c e d b y t h e f a c t o r s o f i n t e n s i t y , p h a s e , and t i m e . A m eth o d -k n o w n a s m a s k in g i s h e a r in g l o s s

fo r v a r io u s f r e q u e n c ie s .

m ean s t h a t t h e e a r i s o th e r ear i s i n m any vretys.

u s e d t o d e t e r m in e t h e

c lo s e d to th e

s t im u la t e d by so u n d s. When m a sk in g i s w i t h

M a sk in g s i m p l e s o u n d s

so u n d w a v e s w h i l e t h e M a sk in g i s t o n e s ,i t

b e t t e r t o m ask w i t h t o n e s b e lo w 7 0 0 c y c l e s

a c c o m p lis h e d is

u s u a lly

th a n th o s e above

700 c y c l e s . A f t e r th e h e a r in g s e n s a t io n h a s b e e n s t im u la t e d , p e r ­ h a p s w i t h a lo u d t o n e , o r f o r a l o n g p e r i o d o f t im e t h e r e may ..be a te m p o r a r y l o s s t io n a f f e c t in g th e

o f t h e f u n c t i o n due t o c e n t r a l n erv o q s sy stem .

a s ta te o f in h ib i­ When t h e

w a v e s a r e v a r i e d , t h e y a r e s a i d t o b e m o d u la t e d . a f f e c t t h e sam e s y s t e m and r e i n f o r c e w hat i s

so u n d

I f tw o t o n e s

one a n o th e r , t h e y p ro d u ce

known a s b e a t s ; t h e s e m u st be o f n e a r l y t h e

same f r e ­

q u e n c y and m u st b e so u n d e d t o g e t h e r i n o r d e r f o r t h e so u n d t o produ ce th e b e a t s .

I f th e r e is

a d if f e r e n c e b e tw e en fr e q u e n -

48 c i e s , an in te r to n e a p p ea rs. "The g e n e r a l p r o b le m o f t h e p s y c h o l o g y o f h e a r i n g i s t h a t o f o b s e r v in g th e a s p e c t s o f so u n d , a s it' a f f e c t s th e o r g a n is m d i r e c t l y ,

and c o m p a r in g t h e r e s u l t s w i t h t h e

ob ser­

v a t i o n s o f t h e a s p e c t s o f so u n d made w i t h t h e h e l p o f i n s t r u ­ m e n t s .” ^

One o f t h e

i n s t r u m e n t s w h ic h h a s d e v e lo p e d an d a f ­

f o r d s t h e m o st r e l i a b l e

an d s c i e n t i f i c m ea su r em e n t o f h e a r ­

i n g i s t h e a u d io m e t e r .

The a u d io m e t e r w as d e s i g n e d t o d e t e r ­

m in e t h e a c u i t y and p o s s i b l y t h e

q u a l i t y o f h e a r in g b y t h r e s h ­

o l d m e a s u r e m e n t, by e l e c t r i c a l s t i m u l a t i o n a s w e l l a s bybone c o n d u c tio n . The a u d io m e t e r h a s a vacuum t u b e o s c i l l a t o r w h ic h p r o ­ d u c e s t o n e s o f s e v e r a l f i x e d f r e q u e n c ie s w here i t s ib le

t o -m easu re i n t e n s i t i e s .

is

a ls o p o s­

T h rou gh t h e r e c e i v e r , t h e

lis ­

t e n e r h e a r s t h e t o n e s w h ic h h a v e b e e n s e t p r e v i o u s l y i n te r m s -o f t h e h e a r in g o f t h e n orm al e a r .

In o rd er to fin d

im p a ir m e n ts o f a n e a r f o r a g i v e n f r e q u e n c y , t h e

ou t th e

o b s e r v e r mea&-

o u r e s t h e am ount b y w h ic h t h e i n t e n s i t y

o f a g i v e n t o n e m ust

b e r a is e d above t h a t f o r a norm al e a r .

T h ese t e s t t o n e s a r e

u s u a l l y s p a c e d a t f r e q u e n c i e s on t h e a u d i b l e r a n g e an o c t a v e a p a r t a l t h o u g h m any b e l i e v e t h a t m ea su rem en t o f h a l f o c t a v e s i s p r e fe r a b le .

T he " n o rm a l” m e a s u r e m e n ts a r e b a s e d o n t h e

"** Ibid, p. 4.

49 h e a r in g o f th o u sa n d s o f youn g p e o p le .

As t h e p a t i e n t i s

t e s t e d , he u s u a l l y h o l d s a r e c e i v e r t o h i s e a r and p r e s s e s a s i g n a l i n g b u t t o n d u r in g t h e e n t i r e t im e he h e a r s a t o n e . The b u t t o n l i g h t s a la m p .

E ach fr e q u e n c y i s t e s t e d i n t h i s

m an n er u n t i l t h e l o w e s t v a l u e i s h ea rs th e to n e . is

T h is v a l u e i s

r e a c h e d a t w h ic h t h e

p a tie n t

t a k e n a s th e t h r e s h o l d ,

com p ared w i t h t h e n o r m a l t o d e t e r m in e t h e

lo s s

and

o f a c u ity

in d e c ib e ls . The r e s u l t s o f t h e a u d i o m e t r ic t e s t s ' a r e p l o t t e d on a n a u d io g r a m .

T he h e a r i n g l o s s

a r b itr a r y p ro ced u re. c e n ta g e s c a le th e

based onean

N e ith e r th e lo g a r it h m e t ic or th e p e r ­

u s e d a g r e e s w i t h t h e p h y s i c a l m ea su rem en t o f

i n t e n s i t y o f th e

a to n e .

in d e c ib e ls i s

s tim u lu s nor th e

s u b je c tiv e

lo u d n e s s o f

T he a u d i o m e t r ic t e s t d o e s n o t r e v e a l a g r e a t d e a l

u n le s s v o ic e t e s t

and a n o t o l o g i c a l e x a m in a t io n f o l l o w .

T h ro u g h t h e s e t e s t s

an d e x a m i n a t i o n s , much h a s b e e n r e v e a l e d

a s t o t h e n a t u r e o f im p a ir m e n ts a s w e l l a s t o t h e

s c ie n tific

str u c tu r e o f th e e a r . S t e v e i l s and D a v is d e s c r i b e t h e e a r b y s a y i n g t h a t i t is

"a v e r y d e l i c a t e a n d h i g h l y c o m p l ic a t e d m e c h a n ic a l d e v i c e —

c e r t a i n l y t h e m o st r e m a r k a b le m e c h a n ic a l s y s t e m i n t h e human body. a b ility

I t s a s t o u n d in g s e n s i t i v i t y t o m in u te d i s t u r b a n c e s ,

its

t o a c q u a in t - t h e b r a i n w i t h d i s p l a c e m e n t s o f t h e e a r ­

drum i ^ i ic h a r e s m a l l e r t h a n t h e d i a m e t e r s o f m o l e c u l e s , and

50 its

p ow er o f r e s o l v i n g

c o m p le x w a v e -fo r m s i n t o

t h e i r F o u r ie r

c o m p o n e n ts , make " th e e a r a m a s t e r p i e c e o f m e c h a n i c a l e n g i ­ n e e r in g .-" 1 The a n a to m y o f t h e m id d le

ear is

very

c o m p l i c a t e d , and

i n i t m o st o f t h e t r o u b l e s and im p a ir m e n ts b e g i n . n a l a u d ito r y c a n a l i s

a p p r o x i m a t e ly 2 . 5 cm. l o n g and 0 . 7

d ia m e t e r *

The i n n e r en d i s

m em b ran e.

The ty m p a n ic m em brane i s

w ith i t s

c lo s e d by th e

cm. i n

e a rd ru m , o r ty m p a n ic

"a c o n e - s h a p e d s t r u c t u r e

a p e x d i r e c t e d in w a r d , w h ic h i s

l_iq..uelyj a c r o s s t h e end o f t h e c a n a l . brane l i e s th e

T he e x t e r ­

p l a c e d som ew hat o b r : :

I n t e r n a l t o t h i s mem­

i r r e g u l a r - s h a p e d c a v i t y o f t h e m id d le

b e t w e e n 1 and 2 c c i n v o lu m e , c o n t a i n i n g t h e t h r e e ( m a l l e u s , i n c u s , an d s t a p e s ) a n d t h e i r

ear,

o s s ic le s

s u p p o r tin g lig a m e n t s .

I n t h e m e d i a l w a l l o f t h e • m i d d l e - e a r c a v i t y a r e tw o o p e n in g s in th e tem p o ra l b o n e, g iv in g a c c e s s t o th e fr o m t h e i r w in d o w .

s h a p e s , a r e known a s t h e

The rou n d w in d o w i s

o v a l w in d ow i s

fille d

t h e m id d le e a r c a v i t y th e n asop h aryn x.

T h ese,

o v a l w in d ow and t h e ro u n d

c o v e r e d b y a m em b ran e, and t h e

by th e f o o t p l a t e

i s h e ld i n p la c e b y e l a s t i c

in n e r e a r .

lig a m e n ts .

o f th e Z

s t a p e s , w h ic h

A n o th e r o p e n in g i n t o

i s t h e E u s t a c h i a n t u b e , w h ic h c o n n e c t s

O r d i n a r i l y , t h e E u s t a c h i a n t u b e , w h ic h c o n ­ s ta n tly

1 I h id , p .

248.

2 I b ia , p.

240.

s ta n tly .is c l o s e d

at i t s

lo w e r e n d , r e g u l a r l y o p e n s d u r in g t h e

a c t o f s w a ll o w i n g and t h e r e b y a l l o w s e q u a l i z a t i o n

of any d i f ­

f e r e n c e i n p r e s s u r e on t h e 'two s i d e s o f t h e ty m p a n ic m e n b r a n e . H e a r in g may b e r e d u c e d i n t h e m id d le e a r b y r e s t r i c ­ t i o n o f m ovem ent o f o s s i c l e s b y a d h e s i o n s ; d i s r u p t i o n o f t h e o s s i c u l a r c h a in ;

a n e x t e n s i v e h o l e i n t h e eard ru m ; l o s s o f

ty m p a n ic m em b ran e, m a l l e u s and i n c u s m ay o r may n o t a f f e c t h e a r i n g b u t h e a r i n g l o s s may b e r e d u c e d t o t h e e x t e n t to

65 d e c i b e l s w h en t h e drum , m a l l e u s ,

I n e x p e r im e n t s w i t h a n i m a l s , b le to

o f 40

and i n c u s a r e m i s s i n g .

i t w as fo u n d t h a t i t w a s p o s s i ­

c u t e n t i r e l y a r o u n d t h e ty m p a n ic m em brane and c a u s e a

h e a r i n g - l o s s o f n o t m ore t h a n 20 or 30 d e c i b e l s .

I t w as a ls o

fo u n d t h a t som e i n d i v i d u a l s may l o s e t h e ty m p a n ic membrane a s w e l l a s t h e m a l l e u s and i n c u s a n d . s t i l l r e t a i n h e a r i n g w i t h i n 2 2 0 o r 30 d b . o f n o r m a l; h o w e v e r , su c h c a s e s a r e e x c e p t i o n a l . The r o u n d w in d o w i s t io n o f th e o f th e

s c a l e t y m p a n i.

e la s tic

and s e r v e s a s t h e t e r m in a ­

C o n s e q u e n t ly , i t a l l o w s m ovem ent

en d o ly m p h an d v i b r a t i o n o f t h e b a s i l a r membrane , and

a l s o s e r v e s a s a p r o t e c t i o n fr o m a i r - b o r n e s o u n d s .

The o s s i ­

c l e s r e s p o n d a s a‘ c l o s e d m a ss t o b o t h lo w an d h i g h t o n e s o f m easu red v i b r a t io n s .

Due t o t h e i r

1 L oo, c i t . 2 I b i d , p p . 2 5 2 -2 5 3 .

e la s tic

su s p e n s io n , th e

52 o s s i c l e s a l l m ove i n s e v e r a l p l a n e s , b a t i n o n e p r e d o m i ­ n a tin g o n e , so t h a t th e sta p e s i s

in c r e a s e d .

The s t a p e s an d w hen t h e p iv o ts ,

a m p lit u d e o f m o t io n d e l i v e r e d t o t h e

**"

■i t s e l f

r o c k s;: " l i k e a b e l l - c r a n k l e v e r ’1

i n t e n s i t y b e c o m e s so g r e a t ,

about th e f o o t p l a t e .

d u c e s m o v em en ts o f t h e l i q u i d m e n ts o f t h e

T h is

it

ro ck s in s te a d of

change o f v i b r a t io n r e ­

and i s p r o t e c t i v e .

The m ove­

s t a p e s a r e a lm o s t e n t i r e l y s y m m e t r ic a l w h i l e t h e

i n c u s sh o w s a l e s s e r d e g r e e o f i t .

The drum , l i g a m e n t s o f

t h e o s s i c l e s and t h e b a s i l a r m em brane a r e a l l e l a s t i c tu r e.

in s tr u c ­

2 T he e f f e c t o f t h e ty m p a n ic membrane on h e a r in g i s

fo u r -fo ld : 1)

’’T h ey p r o v i d e f o r p r e f e r e n t i a l d e l i v e r y o f .s o u n d e n e r g y t o t h e o v a l w ind ow a s o p p o s e d t o t h e r o u n d w in d o w .

2)

"They s e r v e t o c o l l e c t e n e r g y fro m a r e l a ­ t i v e l y l a r g e c r o s s - s e c t i o n o f a i r and d e l i v e r i t t o t h e much s m a l l e r a r e a o f t h e f o o t p l a t e o f th e s t a p e s .

5)

"They p r o v i d e a s l i g h t m e c h a n ic a l r e d u c t i o n i n t h e a m p lit u d e o f m o t io n b e t w e e n t h e ty m ­ p a n i c membrane and t h e p a r t o f t h e s t a p e s w h ic h i s d i r e c t l y *in c o n t a c t w i t h t h e f l u i d o f th e c o c h le a .

4)

" In c o n j u n c t i o n w i t h t h e i n t r a - a u r a l m u s c l e s , t h e y p r o v i d e a p r o t e c t i v e m ec h a n ism f o r t h e

OUi*

|

^

PP# 2 5 4 -2 5 5

2 I b i d . p p . 2 5 5 -2 4 9

53 i n n e r e a r a g a i n s t l o a d lo w t o n e s w it h o u t andue im p a ir m e n t o f h e a r i n g f o r f a i n t t o n e s o f h ig h f r e q u e n c y ." The p h y s i c a l s y s t e m o f v i b r a t i o n r e s i s t s th e v ib r a to r y en erg y .

T here i s

o f t h e e a r and t h e t h r e s h o l d lo w a h u n d r e d , t h e

a r e la tio n

b e tw e e n im p e d a n c e

of s e n s it iv it y .

im p e d a n ce o f t h e

or im p e d e s

At c y c l e s be-^

e a r i s d e t e r m in e d b y t h e

drum o s s i c l e s and i n n e r e a r a s w e l l a s b y t h e

a ir i t s e l f .

The a i r - c u s h i o n a c t s a s a p r o t e c t i v e m e c h a n ism a g a i n s t s u d ­ d en e h a n g e s i n p r e s s u r e o r l o u d so u n d s o f lo w f r e q u e n c y . The m a s t o id a i r - c e l l s f e r c o n s id e r a b ly in

c o m m u n ic a tin g w i t h t h e m id d le e a r d i f ­

t h e i n d i v i d u a l and may a b s o r b so u n d an d

c h a n g e t h e r e s o n a n c e o f t h e m id d le e a r . I t h a s b e e n fo u n d p o s s i b l e t o m ake s e v e r a l d i r e c t m e a s u r e m e n ts o f t h e n a t u r a l p e r i o d o f v i b r a t i o n o f t h e in i t s

resp o n se to

ear

su d d e n b r i e f d i s t u r b a n c e s .

"K obrak g i v e s a d am p in g f a c t o r e q u a l t o a b o u t o n e - h a l f t h e v a l u e f o r c r i t i c a l d a m p in g . U n d e r t h i s d am p in g t h e a u d i t o r y m e c h a n ism e x e c u t e s a f e w r a p i d l y damped o s c i l l a t i o n s a t i t s n a t u r a l p e r i o d f o l l o w i n g su d d e n d i s p l a c e m e n t fr o m i t s p o ­ s i t i o n a t r e s t and a l s o f o l l o w i n g t h e s u d d e n o n ­ s e t o f c e s s a t io n o f s tr o n g s t im u la t io n a t any fr e q u e n c y . . . The b a s i l a r m em b ran e, a l t h o u g h d i f f e r e n t i a l l y s e n s i t i v e in v a r io u s r e g io n s to d if f e r e n t f r e q u e n c ie s , ap p ears to be e s s e n t i a l l y c r i t i c a l l y dam ped, f o r t h e e l e c t r i c a l a c t i v i t y

1 I b i a . p.

259.

54 o f t h e c o c h l e a s h o w s , a s an ,fo f f - e f f e c t , ft o n l y a n o n s p e c i f i c n a t u r a l p e r i o d .w h ich p r o b a b l y d e ­ p e n d s u p o n t h e v i b r a t i n g s t r u c t u r e s o f t h e m id ­ d le e a r. The dam ping f a c t o r , and a l s o t h e n a t u ­ r a l p e r io d o f th e s t r u c t u r e s o f t h e m id d le e a r , a r e a l t e r e d b y c o n t r a c t i o n o f t h e t e n s o r ty m p a n i and t h e s t a p e d i u s m u s c l e s . The t r a n s m i s s i o n f a c t o r i s r e d u c e d b y 30 p e r c e n t and th e e l a s t i c com p o n en t o f t h e im p e d a n c e i s i n c r e a s e d d u r i n g v o lu n ta r y c o n tr u c tio n o f th e s e m u s c le s ." 1 S o u n d s may b e t r a n s m i t t e d t o t h e t h r e e w ays:

in n e r e a r by

1)

By t h e o s s i c u l a r c h a i n a c r o s s t h e m id d le e a r f r o m t h e t y m p a n i c membrane t o t h e o v a l w in d o w .

2)

B y t h e t y m p a n i c membrane a c r o s s t h e m i d d le e a r b y m ean s o f a i r w a v e s i n s t e a d o f th e o s s ic le s .

3)

B y t h e w a l l s o f t h e c a n a l and t r a n s m i t t e d t h r o u g h t h e b o n e s o f t h e s k u l l a r o u n d th e m id d le e a r t o t h e in n e r e a r , o r b y bone c o n d u c tio n , or by th e b on es o f t h e s k u l l e n tir e ly . 2

The i n t e r n a l e a r a n d ~ i t s s e n s e o r g a n o f h e a r i n g i s c a ted in th e

l a b y r i n t h or t e m p o r a l b o n e o f t h e

tw o p a r t s of t h e l a b y r i n t h a r e th e la b y r in th s .

flu id ,

c o c h le a .

of th e v e s t i b u l e ,

T hese c o n ta in

t h e p e r i l y m p h and t h e m e n b r a n e o u s l a b y r i n t h .

1 Ibdd, p .

259.

2 Ibid, pp. 262-263.

The

o s s e o u s and t h e m em b ran eou s

The o s s e o u s l a b y r i n t h c o n s i s t s

s e m i - c i r c u l a r c a n a l s , and t h e

sk u ll.

lo ­

a c le a r

55 The c o c h l e a r e c e i v e s t h e s o u n d . sh e ll"

s h a p e , and i s

lo c a te d

in fro n t o f th e v e s tib u le .

c o n s i s t s o f t h e m o d i o l u s an d a c a n a l . o p e n in g s:

I t has a " s n a il-

The c a n a l h a s t h r e e *

on e f o r t h e r o u n d - w in d o w , o n e i n t o t h e

and o n e a t ^ t h e e n d o f t h e c o c h l e a r a q u e d u c t , la b y r in th l i e s

i n t h e bony c a v i t i e s .

It

v e stib u le ,

.T h e m em b ran eou s

I t h a s t w o s a c s i n w h ic h

are lo c a te d th e se n s o r y c e lls - w h ic h are con cern ed w ith h e a r in g .

T h r e e p o r t i o n s o f t h e b a s i l a r membrane a r e t h e

v e stib u le ,

s c a l e m ed ia ,

and s c a l a t y m p a n i .

T he o r g a n o f C o r t i c o n s i s t s o f a s e r i e s a lo n g th e

i n n e r e d g e o f t h e b a s i l a r m em b ran e.

r o d s fo r m a t r i a n g l e

sc a le

of stru ctu res Two r o w s o f

and d i v i d e t h e o r g a n o f C o r t i .

On t h e

i n n e r s i d e s o f t h e i n n e r r o d s a r e fo u n d t h e i n n e r h a i r c e l l s in a

sin g le

r o w , and on t h e o u t e r s i d e s o f t h e o u t e r r o d s a r e

e x te r n a l h a ir c e l l s

and s u p p o r t i n g c e l l s .

The

end f i b e r s o f

th e a c o u s t i c n e r v e c o n t a c t t h e s e h a i r c e l l s fo rm in g th e organ o f h e a r in g .

1

T here a r e a p p r o x im a te ly 5500 h a i r - c e l l s in t h e i n n e r row and a b o u t 2 0 , 0 0 0 d i v i d e d among t h e th r e e o u te r row s. The i n n e r h a i r c e l l s a r e s l i g h t ­ l y la r g e r (1 2 m icr o n s) in d ia m e ter th a n th e o u t e r h a i r c e l l s ( 8 m i c r o n s ) and t h e d i m e n s i o n s o f e a c h t y p e a r e c o n s t a n t a l o n g t h e b a s i l a r m em brane. B oth t h e i n t e r n a l and t h e e x t e r n a l h a i r - o e l l s a r e q u i t e e v e n l y s p a c e d a l o n g t h e b a s i l a r m em brane.

1 Ibid. PP. 271-272.

56 T h e r e a r e b e t w e e n 2 5 , 0 0 0 and 2 9 , 0 0 0 g a n g l i o n c e l l s in th e s p ir a l g a n g lio n o f th e C o rti w ith in th e m o d io lu s. They a r e n o t e v e n l y d i s t r i b u t e d a l o n g t h e l e n g t h o f t h e b a s i l a r m em brane, b e i n g m ore d e n s e l y c o n g r e g a t e d i n t h e u p p e r p o r t i o n o f t h e b a s a l t u r n an d f e w e s t i n t h e u p p e r m i d d l e and a p ic a l se c tio n s. The a v e r a g e nu m bers p e r m u l l i m e te r a r e : lo w e r b a s a l , 934; upper b a s a l , 1076; l o w e r m i d d l e , 9 7 1 ; u p p e r m i d d l e and a p i c a l 5 0 2 . E a c h i n n e r h a i r c e l l i s i n n e r v a t e d b y o n e or tw o n e r v e - f i b e r s , and e a c h n e r v e - f i b e r m a k e s c o n ­ n e c t i o n s w i t h on e o r tw o h a i r c e l l s . . . The e x te r n a l h a ir c e l l s , how ever, have m u ltip le in n e r ­ v a tio n . A n e r v e - f i b e r may c o n n e c t w i t h many e x ­ t e r n a l h a i r - c e l l s , e x te n d in g over a range of a s much a s o n e - h a l f o f a t u r n , and e a c h h a i r - c e l l may be c o n n e c te d w it h s e v e r a l n e r v e f i b e r s . The n e r v e f i b e r s to th e o u te r row s o f c e l l s p a s s ou t r a d i a l l y from t h e s p i r a l g a n g l i o n , c r o s s t h e t u n n e l o f t h e o r g a n o f C o r t i , a n d , upon a r r i v i n g i n t h e o u t e r r o w s , t u r n s h a r p l y . . a n d p a s s down to w a r d t h e b a s a l end o f th e c o c h le a . The v i c o s i t y o f t h e f l u i d b a s i l a r membrane h i g h l y dam ped.

i n _ i h e c o c h l e a m akes t h e T h i s d a m p in g r e d u c e s t h e

r e v o l v i n g p o w e r i n t h e a n a l y s i s o f t hm so u n d w a v e s . a s a v i b r a t i n g s t r u c t u r e , t h e b a s i l a r membrane i s a s a d a m p in g f a c t o r .

T h is i s

H ow ever,

im p o r t a n t

i n d i c a t e d b y t h e r a p i d i t y by

w h ic h s o u n d v i b r a t i o n s d i e a f t e r th© s t i m u l u s h a s c e a s e d . A l l c e l l s h a v e c e r t a i n e l e c t r i c a l p r o p e r t i e s , and a s do t i s s u e - f l u i d s , t h e y a l l h a v in g t h e a b i l i t y t o

c o 'h t a in e l e c t r o l y t e s

conduct e l e c t r i c i t y .

su red by e l e c t r i c a l r e s i s t a n c e .

1 Ibid. pp. 296-305.

in s o lu tio n

T h i s may b e m ea­

I o n s a r e l i m i t e d i n movement

57 b y s t r u c t u r e o f t h e p r o t o p l a s m b y m em branes and o r g a n i z a t i o n o f th e

c e lls*

T h ro u g h t h e p r o c e s s o f p l a c i n g a n e l e c t r o d e i n

c o n ta c t w ith th e

in t e r io r of th e c e l l ,

th e d if f e r e n c e

p o t e n t i a l or i n j u r y - p o t e n t i a 1 c a u s e s i t u rem en t.

of th e

t o b e c a p a b l e o f m eas­

T h e tw o t y p e s o f e l e c t r i c a l c h a n g e s a r e d i s t o r t i o n -

p o t e n t i a l s and a c t i o n p o t e n t i a l s f o l l o w i n g t h e a l l - o r - n o n e la w .

F o llo w in g t h i s la w , th e

c e ll is

in e x c ita b le

for

a lo n g

t im e w h ic h h a s b e e n d e s i g n a t e d a s t h e a b s o l u t e r e f a c t o r y p e r i ­ od.

R e c o v e r y c o n t i n u e s t h r o u g h tb e

r e la tiv e

r e fa c to r y p e r io d .

T h en f o l l o w s a p r o c e s s o f e q u i l i b r a t i o n and f a t i g u e c h a r a c te r istic

of a ll-o r -n o n e r e sp o n se s.

w h ic h i s

The c h e m i c a l s u b ­

s t a n c e s a re l i b e r a t e d a t t h e n e r v e e n d in g s c a u s in g m e c h a n ic a l c o n tr a c tio n .

T he p r i n c i p l e s

o f asym m etry, o r i e n t a t i o n ,

and

sy n c h r o n iz a tio n a re n e c e ss a r y in th e stu d y of c e l l u l a r p o te n ­ tia ls .

T h ro u g h t h e p r o c e s s o f s y n c h r o n i z a t i o n ,

it

is

p o ssib le

to

s t u d y t h e a c t i v i t y o f a u d i t o r y p a t h w a y s and t h e m i e r o p h o n i c 1 a c t i o n o f th e c o c h le a a s a w h o le . T h is a l l - o r - n o n e la w o f th e n e r v e -im p u ls e i s n if ic a n t in h e a r in g .

A l l n e r v e im p u lse s a r e fu n d a m e n ta lly

t h e sam e, a lth o u g h t h e i r

s p e e d , w h eth er m easured a s a v e l o c i t y

o f c o n d u c tio n or a s th e r a te p o in t, tio n

v a r ie s

of s iz e .

L oc.

very s i g ­

o f e l e c t r i c a l change a t a g iv e n

s y s t e m a t i c a l l y from f i b e r to f i b e r a s a f u n c ­ H ow ever, th e r a t e

c it.

is

co n sta n t fo r a g iv e n f i b e r

58 a lth o u g h o n ly one k in d o f n e r v e im p u lse h a s b e e n d e t e c t e d . The o n l y r a p i d c h a n g e w h i c h p r o c e e d s a l o n g an a f f e r e n t n e r v e fib e r is

t h e n e r v e - i m p u l s e w h ic h i s

a ll-o r -n o n e

in ch a ra cter

w h i l e t h e i n t e n s i t y and d u r a t i o n v a r i e s w i t h f a t i g u e . The p h y s i o l o g i c a l v a r i a b l e s i n t h e —a f f e r e n t lim ite d as fo llo w s: m a tte r o f (1 )

”T h e r e i s

^

n e r v e are

s i g n i f i c a n t freed o m i n t h e

how many f i b e r s and o f

( 2 ) w h ic h f i b e r s i n

t h e n e r v e may c a r r y i m p u l s e s , and o f w h e t h e r ( 3 ) on e o r s e v ­ e r a l i m p u l s e s p a s s up e a c h f i b e r what f r e q u e n c y .

and, w i t h i n l i m i t s , (4 )

T h ere i s no v a r i a t i o n i n th e

siz e

at

o f the

im p u lse a s a f u n c t i o n o f t h e i n t e n s i t y o f t h e

stim u lu s.

is

of im p u lse s in

a l s o freed om i n

(5 )

t h e tem p oral r e l a t i o n s

T here

d if f e r e n t f i b e r s , s in c e each f i b e r i s f u n c t io n a lly q u ite in £ dependent o f i t s n e i g h b o r s .” P s y c h o p h y s i o l o g y m u st e x a m in e t h e a c t i v i t y o f t h e c o c h ­ le a

and t h e a u d i t o r y n e r v e t o

com pare a u d i t o r y s e n s a t i o n s i n

o r d e r t o d e ter m in e t h e a u d it o r y s e n s a t i o n . n e r v e -fib e r s

is

th at

The f u n c t i o n o f

o f c o n d u c t i o n , and t h e i m p u l s e s m u st b e

f o u n d , t h e i r a c t i v i t y a t t h e s y n a p t i c c e n t e r s m u st b e i n t e r ­ p reted , in g i s

and t h e i r m e s s a g e s t r a n s l a t e d .

The a n a to m y o f h e a r ­

c o m p l i c a t e d b y t h e s y n a p s e s a s t h e y h a v e new p h y s i o -

1 L o£ .

c it.

2 Ib id , p.

506.

59 l o g i c a l l a w s and d i f f e r e n t v a r i a b l e s f r o m t h e o t h e r s , a new p a t t e r n Of a c t i v i t y .

Some o f t h e v a r i a b l e p r o p e r t i e s o f t h e

synapses in th e s p in a l r e fle x e s are: (1)

O ne-w ay c o n d u c t i o n i n t h e s y n a p s e fr o m th e axon a c r o s s th e syn ap se to th e den­ d r i t e or c e l l b o d y b a t n o t i n r e v e r s e d i ­ r e c tio n .

(2 )

G r e a te r s e n s i t i v i t y o f the sy n a p se t o a d ­ v e r se c o n d itio n s — A n e s th e tic d ru gs, f a t i g u e , and la c k o f oxygen s t o p s y n a p tic c o n d u c tio n .

(3 )

D e la y in c o n d u c tio n th rou gh th e syn ap se a s com p ared w i t h t h a t c f t h e a x o n s .

(4)

Su m m ation o f i m p u l s e s a t t h e s y n a p s e s . I t is n e c e s s a r y f o r s e v e r a l im p u ls e s to a r r iv e , e i t h e r ( a ) i n s u c c e s s i o n o v e r t h e same a x o n , g i v i n g t e m p o r a l s u m m a t io n , o r ( b ) n e a r l y sim u lta n e o u sly o v er d if f e r e n t axon s, g iv in g s p a t i a l s u m m a tio n .

(5)

I n h ib it io n a t sy n a p tic ju n c tio n s . Im p u lse s a t c e r ta in sy n a p ses ten d to su p p r e ss a c t i v i t y i n p r o c e s s a n d make n e u r o n s m ore r e s i s t a n t t o o th e r im p u lse s o f o th e r p ath w ays.

(6)

S p o n ta n eo u s a c t i v i t y o f g ra y m a tte r . The c e n t r a l a c t i o n o f g r a y m a t t e r i n c h e m i c a l or e l e c t r i c a l e v e n ts o c cu rin g i n th e n erv o u s s y s t e m i s unknown y e t . 1

The a u d i t o r y n e r v e i s b e t w e e n t h e b r a in . th e

sense

o r g a n and t h e

S o u n d - w a v e s i n i t i a t e m o v e m e n ts i n t h e s t r u c t u r e s o f

i n n e r e a r w h i c h a r e s t u d i e d a n d a n a l y z e d by a u r a l m i c r o ­

p h o n ic s.

By i m p u l s e s i n t h e _ _ a u d i t o r y n e r v e , t h e

s e n s e organ

a f f e c t s t h e h i g h e r n e r v o u s c e n t e r s and t h e s e r e a c t i o n s a r e

1 I b i d , PP. 3 0 7 - 3 0 9 .

c a lle d

se n s a tio n s.

T hese im p u lse s p o s s e s s c e r t a i n p r o p e r t i e s .

The f i b e r s o f t h e n e r v e a r e s p i r a l i n a r r a n g e m e n t and connect th e

c o c h l e a r n u c l e u s w i t h t h e b a s i l a r membrane c o n ­

s t i t u t i n g th e nerve a x is .

O ther f i b e r s are t w i s t e d around

t h e s e - w h i c h go t o t h e a p e x and b a s a l r e g i o n . th e m e d u lla , th e f i b e r s

When t h e y e n t e r

d i v i d e and t h e a s c e n d in g b ra n ch g o e s

t o t h e g a n g l i o n v e n t r a l e and t h e d e s c e n d i n g b r a n c h g o e s t o th e tu b er cu lu m a c u s tic u m .

T h e s e b ^ sth e h e s a r e i n p a r a l l e l

b u n d le s.

it

In th e v e n tr a le ,

r e p r e s e n ts a p r o j e c t io n in th e

c o c h le a r n u c le u s o f th e organ o f C o r ti. The a l l - o r - n o n e

im p u lse

is

th e p h y s io lo g ic a l u n it

n e r v o u s a c t i v i t y , and th e r e s p o n s e t o n a l s t i m u l a t i o n m u st c o n s i s t E ach sou nd -w ave i s

its e lf

of

of th e a u d ito r y n erve to

of a se r ie s

of su ch im p u lse s.

a sep a ra te stim u lu s,

and n e r v e im ­

p u l s e s grou p t h e m s e lv e s i n r e l a t i o n t o sou nd w a v es a s im p u l­ se s in th e ly .

H ow ever, i t

from th e en t,

c o c h le a r n u c le u s have not been s tu d ie d s u f f i c i e n t ­ is

known t h a t t h e l o n g c e l l s

c o c h le a r n u c le u s to h ig h e r c e n te r s ;

b u t t h e s h o r t a x o n s do n o t

n u c le u s.

convey im p u lse s th e y are e f f e r ­

e x te n d beyond t h e

c o c h le a r

The d i f f e r e n t f i b e r s f o r m d i f f e r e n t c e n t r a l c o n n e c ­

t i o n s and c o n t r i b u t e m ore t h a n do t h e o t h e r s t o t h e nervous sy stem .

c en tra l

O n ly b y i n c r e a s i n g t h e number o f a c t i v e f i ­

b e r s i s t h e r e an i n c r e a s e i n t h e

a c t i v i t y of th e a u d ito r y

n e r v e , f o r l o u d n e s s is^ n o t ] p r o p o r t i o n a l t o t h e num ber o f f i b e r s .

61

At l o w f r e q u e n c i e s , t h e f r e q u e n c y o f n e r v e i m p u l s e s i s d e ­ te r m in e d by sound w a v e s . f o r im p u ls iv e s t i m u l i i s th e th r e sh o ld

T he t h r e s h o l d o f n e r v e i m p u l s e s d e t e c t e d by a u r a l m ic r o p h o n ic s and

o f h e a r i n g . -*•

The c e r e b r a l c o r t e x i s t h e h i g h e s t vous system .

T here i s

little

k n o w le d g e o f t h e n e r v o u s s y s t e m

b e y o n d t h e c o c h l e a and S y l v i a n f i s s u r e H ere th e p a th w a y s d i v i d e , m erous t h a t i t

is

le v e l of th e n er­

of th e tem p o ra l lo b e .

and t h e i n t e r c o n n e c t i o n s a r e s o n u ­

im p o ssib le

to d e sig n a te th e a u d ito r y o n e s.

D is e a s e s o f h e a r in g r e l a t i n g t o th e

se n se -o r g a n , a u d ito r y

n e r v e s , and h i g h e r p a t h w a y s m a n i f e s t t h e m s e l v e s b y a l o s s o f a c u ity , n e sia ,

lo ss lo ss

of fu n c tio n o f th e c er e b ra l c o r te x , o f m e a n in g o f a l l s o u n d s ,

or w o rd s,

a p h a sia ,

am­

and a u d i t o r y

h a llu c in a t i o n s . The c e r e b r a l c o r t e x i s tio n s of e le c tr ic p o te n tia ls.

t h e c e n t e r o f r h y t h m ic f l u c t u a ­ T hese e l e c t r i c a l w aves are

s l o w e r t h a n t h e a c t i o n p o t e n t i a l s , and a c t i v i t y i s o r d e c r e a s e d by s e n s o r y s t i m u l a t i o n .

in c rea se d

T hese p a tte r n s a r e s im i­

l a r i n v o l t a g e , w a v e - f o r m and r h y th m i n a l l p a r t s o f t h e g r a y m a tter.

A g r e a t d e a l more n e e d s t o b e l e a r n e d c o n c e r n i n g t h e ;2 e l e c t r i c a l a c t i v i t y o f th e c o r te x in r e la t io n to h e a r in g .'

^ I b id , p p .4 1 4 -4 3 2 . 2 I b i d , pp. 4 2 0 -4 3 2 .

62

The c e l l b o d i e s o f t h e p r i m a r y n e u r o n s c o n s t i t u t e t h e a u d ito r y nerve* le a .

T h ey a r e l o c a t e d

in t h e m o d io lu s o f th e

The p r i m a r y a f f e r e n t n e u r o n t e r m i n a t e s i n t h e

n u c le u s or g r a y m a tte r in th e m e d u lla -a t th e p o in t o f th e a u d ito r y n e r v e.

coch­

c o c h le a r of en try

H ere t h e p r im a ry n e u r o n s form s y n a p t i c

c o n n e c tio n s w it h 'seco n d -o rd er n eu ro n s.

T h ese p ath w ays a r e

in t e r r u p t e d by s y n a p s e .

The t h i r d - o r d e r n e u r o n s c o n v e r g e i n

th e a u d ito r y p ath t o th e

cereb ral co rtex .

The f o u r t h o r d e r

n e u r o n s c o n n e c t t h e m e d i a l g e n i c u l a t e b o d y and t h e c e r e b r a l c o r te x by a u d ito r y r a d ia tio n s . fa n .

T h ese r a d i a t io n s r ese m b le a

T h e y i n c l u d e f i b e r s g o i n g fr o m t h e

g e n ic u la te body.

c o r te x to th e m ed ia l

A few o f th e f i b e r s r e a c h th e te m p o r a l l o b e .

M ost o f th e m e n t e r t h e n u c l e a r z o n e o f t h e a u d i t o r y c o r t e x . A l l t h e f i b e r s m u st p a s s t h r o u g h t h i s z o n e . The c o c h l e a r n u c l e u s i s n ervou s sy stem .

The p r i m a r y c o c h l e a r f i b e r s a r e v e r y c o m p l i ­

c a ted s t r u c tu r e s .

Each f i b e r

a r e grouped i n t h i r t e e n neurons.

t y p i c a l o f t h a t found i n t h e

c o n n e c t s n u m ero u s c e l l s w h ic h

or more r e g i o n s o f d i f f e r e n t

There a r e f o r t y or f i f t y

typ es of

ty p e s of neurons p r esen t

i n t h e c o c h l e a r n u c l e i and e a c h f i b e r c o n n e c t s h u n d r e d s and th o u sa n d s o f c e l l s . c o r d in g t o th e

The c e l l s

are d iv id e d in to

lo n g or s h o r t a x o n s.

c la s se s ac-

~

The h a i r c e l l t h e o r y o f t h e a u r a l m i c r o p h o n i c s i s a ll,

or n e a r l y a l l o f t h e m i c r o p h o n i c e f f e c t s

o f th e

th a t

c o c h le a

d e p e n d u p o n t h e w ork o f t h e h a i r c e l l s

o f th e organ o f C o r ti*

The c e l l s no l o n g e r g e n e r a t e m i c r o p h o n i e s when t h e y g e n e r a t e s o t h a t t h e n u c l e i a r e no l o n g e r n o r m a l i n a p p e a r a n c e o r h a v e u n d e r g o n e 1 m arked s w e l l i n g * hut convert i t

H a ir c e l l s

do n o t s u p p l y e n e r g y , 1 fro m a m e c h a n i c a l t o an e l e c t r i c a l form * The

a c o u s t i c a l a n d e l e c t r i c a l p o w e r c a n n o t b e a c c u r a t e l y c o m p u te d . The m i c r o p h o n i e a c t i o n o f t h e c o c h l e a a c t i o n o f th e c o c h le a *

sh o w s t h e m e c h a n i c a l

C o c h le a r m ic r o p h o n ic s a re used in

s t u d y in g t h e t r a n s m i s s i o n o f sou nd a c r o s s th e m id d le e a r an d i n t o

th e organ o f C o r ti*

The q u a n t i t a t i v e r e l a t i o n o f

t h e c o c h l e a r m i c r o p h o n i c s may h e a n a l y z e d a c c o r d i n g TT( a ) th e p o s i t i o n o f th e r e c o r d in g e l e c t r o d e s , sity ,

and ( c ) t o f r e q u e n c y . ”

is

e l e c t r i c a l w aves.

In t h is

The p o t e n t i a l s

resp ect

C o n se q u e n tly ,

c a p a b le o f c o n v e r tin g a l t e r n a t i n g c u r r e n ts

c h a n ic a l v ib r a t io n s .

so u n d -in te n -

o f th e ear in con­

I t a c t s a s an e le c t r o m e c h a n ic a l tr a n s d u c e r * it

to

2

M ic r o p h o n ic s d e n o te th e a c t i v i t y v e r t i n g so u n d w a v e s i n t o

(b )

i n t o me­

reproduce th e freq u en cy

a n d t h e w ave fo r m o f s o u n d - w a v e s t h r o u g h o u t t h e r a n g e o f a u d ib le fr e q u e n c ie s .

The c o c h l e a r m i c r o p h o n i e i s

tin u o u s f u n c t io n o f th e i n t e n s i t y

1 IM i,

PP> 4 1 6 - 4 2 0 .

2 I M S . p* 4 7 1 *

to

o f th e stim u lu s*

a con­ The

64 l o w e s t v a l u e o f ttip s t i m u l u s w i l l p r o d u c e a c o c h l e a r m i c r o ­ p h o n i e d e p e n d i n g on t h e n a t u r e o f t h e e l e c t r i c i t y . l o w and v e r y h i g h f r e q u e n c i e s m ore e n e r g y i s

At v e r y

n e c e ssa r y to

p rod u ce a m ic r o p h o n ie e f f e c t . The w ave fo r m o f t h e th e

s t i m u l a t i n g sou n d -w ave.

m ic r o p h o n ic s t o be d i f f i c u l t q u e n c ie s , but

it

c o c h le a r p o t e n t i a l i s In terferen ce

sim ila r to

cau ses th e

o f m ea su r em e n t a t

c o c h le a r

c e r ta in f r e ­

" r e f l e c t s w ith g r e a t a c c u r a c y t h e tim e c o u r se

and w a v e -fo rm o f t h e m e c h a n ic a l d is t u r b a n c e w i t h i n t h e c o c h ­ le a ."

T h e c o m p le x a c o u s t i c

s e le c tiv e

s e n s itiv ity

1 Ib id , p. 317.

sp ectru m i s

c o n d itio n e d by th e

o f t h e e a r ’ s r e s p o n s e . ***

CHAPTER III THE RELATION OF SPEECH AND HEARING TO SHORTHAND I n H i s b o o k , The H a n d ic a p o f D e a f n e s s , Dr* E w in g sta tes,

”T he w ord i s

a k in d o f sh o r th a n d s y m b o l . T h i s

sen­

t e n c e e x p r e s s e s t h e i n t e r r e l a t e d n e s s o f t h e im p o r ta n t a s p e c t s odf sten og rap h y.

la st

a s sh orth an d , i s

a s t u d y o f s y m b o ls f o r

w o r d s , s o w o r d s a r e s y m b o ls o f m e a n i n g f u l i m p r e s s i o n s o f t h e m in d ; and s p e e c h , la ted

s h o r t h a n d , and h e a r i n g a r e v e r y c l o s e l y r e ­

in sten o g ra p h y .

terested

For y e a r s p s y c h o l o g is t s have been i n ­

i n t h e c o r r e l a t i o n o f t h e r e a d in g r a t e , com prehen­

sio n r a te ,

and v o c a b u la r y w it h i n t e l l i g e n c e ,

th ereb y in d ic a ­

t i n g t h a t w o r d s a r e s y m b o ls o f a f a r m ore s i g n i f i c a n t m e n t a l p rocess. S tu d ie s have proved th a t d e a fn e s s i s c a tio n o f th e la c k of l i n g u i s t i c la c k o f su ch m en ta l t r a i t s and e y e - h a n d c o o r d i n a t i o n .

u s u a lly an in d i­

a b i l i t y r a t h e r th a n o f th e

a s m ovem ents, s p a c e p e r c e p t i o n , H e n c e , lo w i n t e l l i g e n c e

q u o tie n t

d o e s n o t n e c e s s a r i l y m ean t h a t s t u d e n t s l a c k m e n t a l c a p a c i t y , but th a t t h e y have b een d e p r iv ed o f l i n g u i s t i c

i

a b i l i t y w h ic h

Hugo F r e y , ”The P s y c h o l o g i c a l A s p e c t s o f D e a f n e s s . ” J o u r n a l o f L a r y n g o l o g y and O t o l o g y , 5 6 : 2 0 9 , M arch , 1 9 4 1 .

66 w o u ld h a v e g i v e n th e m a m ore a d e q u a t e b a c k g r o u n d f o r s e n s e p e r c e p tio n .

B e c a u s e many h a r d - o f - h e a r i n g a n d d e a f p e o p l e

sh o w a v e r a g e m o t o r a b i l i t y , r in g m otor a b i l i t y

s c h o o ls have o c c u p a tio n s in v o lv e

a s on© o f t h e i m p o r t a n t a s p e c t s o f t h e i r

t h e r a p e u tic program s.

T hus,

sp eech i s

a sym bol o f k n o w le d g e ,

and k n o w l e d g e i n d i c a t e s v a r i o u s d e g r e e s o f i n t e l l i g e n c e a s c o m p u te d b y t h e u s u a l s t a t i s t i c a l m e t h o d s o f p s y c h o l o g y . T h en w h at i s

s p e e c h , and how d o e s t h i s

p r o c e s s o f w h i c h many a r e d e n i e d , f u n c t i o n ? T r a v is s t a t e s t h a t sp eech i s t i o n and s y n t h e s i s

a l l im p o r ta n t Dr* L ee Edward

a d y n a m ic p r o c e s s o f a c o m b in a ­

o f e le m e n ta r y f u n c t io n s

”w i t h w i d e s t com­

b in a tio n s o f s tim u li d if f e r e n t in o r ig in , f e e l in g , --s ig n ific a n c e .”

He a l s o

a i m , and

c o n s i d e r s t h a t o f a l l o f t h e m ove­

m e n t s , t h o s e o f e x p r e s s i o n c o m p r i s e t h e l a r g e s t num ber o f d i ­ v e r s e e l e m e n t s , and t h a t

”The c o m p l e t e a c t i n i t s p e r f e c t

f o r m dem ands t h e m o b i l i z a t i o n i n p r o p e r s e q u e n c y o f a s e r i e s o f c o m p le x p r o c e d u r e s w h e r e i n t h e t i m e r e l a t i o n m e n ta l im p o r ta n c e.

is

o f fu n d a­

A w an t o f c h r o n o l o g i c a l e x a c t i t u d e w i l l

t h r o w t h e w h o le p e r f o r m a n c e i n t o d i s o r d e r . ”1 A l t h o u g h t h e m e c h a n ism o f s p e e c h o f t h e v a r i o u s l a n ­ g u a g e s and r a c e s i s ’som ew hat d i f f e r e n t f r o m .the o t h e r s , t h e

L ee Edward T r a v i s , S p e e c h P a t h o l o g y . 4. D ynam ic N e u r o l o g i c a l T r e a t m e n t o f Nor m a l S p e e c h and S p e e c h D e v i a ­ t i o n s , (New k o r k : D. A p p l e t o n - C e n t u r y Company, 1 9 3 1 } , pp. 2 32 -25 3.

67 g e n e r a l m e c h a n is m o f p r o d u c i n g s p e e c h i s p le ;

hence, th ere

sounds.

T h is ,

is

a great

of course,

s im ila r ity

sim ila r fo r a l l peo­ o f fu n d a m en ta l sp ee ch

i s tru e as th e r e

is

a lim ite d range

o f s o u n d s t h a t c a n h e made b y t h e o r g a n o f s p e e c h . gan c o n s i s t s o f th e lu n g s , lip s,

vocal p assages,

T h is o r ­

v o ca l co rd s, to n g u e,

and . c a v i t i e s o f t h e n o s e and t h r o a t . T h erefore,

it

is

by t h e p r o c e s s o f h e a r i n g t h a t t h e

i m p o r t a n t s o u r c e s o f s t i m u l a t i o n f o r t h e d e v e lo p m e n t a n d m a in ­ ten a n ce

of s p e e c h i s

r e c e iv e d .

C om plex s o u n d s a r e c o m b in a ­

t i o n s and v a r i a t i o n s o f p u r e o n e s .

V ib r a tio n s in th e

w ave s t a r t v i b r a t i o n s i n t h e e a r drum .

IThen t h e s e

so u n d

stim u li

a r e c o m m u n ic a te d t o t h e i n n e r e a r , t h e y e x c i t e t h e n e r v e e n d ­ in g s t o s e t

up n e r v e i m p u l s e s .

From t h e r e ,

th e n erv e im p u lse s

a re co n d u cted b y way o f th e a u d it o r y n e r v e t o th e b r a in . th ere is

any d e f e c t

i n any p a r t

If

o f t h i s c o n d u c t in g and r e c e i v ­

i n g m e c h a n is m , t h e b r a i n w i l l n o t b e p r o p e r l y s t i m u l a t e d , and sp eech w i l l in d ic a te

im p a ir m e n t o f t h e m e c h a n is m . 1

In sp eech , ton e c o n s is t s p i t c h and l o u d n e s s , q u e n c y and i n t e n s i t y o f t o n e w h ic h i s m ean s o f t h e

of th e

sen sory p r o p e r tie s of

and o f t h e p h y s i c a l p r o p e r t i e s o f f r e ­ o f v i b r a t i o n , a n d v o lu m e o r e x t e n s i t y

r e l a t e d t o b o t h i n t e n s i t y and p i t c h .

o p t ic a l curve a n a ly s is

By

o f b r e a k i n g down c o m p le x

s o u n d s and p r o j e c t i n g th e m o n t o a v a r i a b l e d e n s i t y r e c o r d ,

1Ibid, p. 204..

68

v a r i o u s h a r m o n i c s o f so u n d may be m e a s u r e d . -*• r io u s a n a ly s e s ,

it

in freq u en cy

w e l l a s i n i n t e n s i t y , —b u t t h a t t h e y may s t i l l

tis

h as b een fou n d t h a t

A lso , by va­

appear i d e n t i c a l to th e e a r .

so u n d w a v e s may d i f f e r

"The f r e q u e n c y i s a s s o c i a t e d

w i t h th e r a p i d i t y o f - v i b r a t i o n o f t h e sound s o u r c e , i n t e n s i t y w i t h t h e pow er t h a t i s sou rce.

and t h e

r a d ia te d by th e v ib r a t in g

The c o r r e s p o n d i n g a s p e c t s o f t h e s e n s a t i o n o f t o n e

w h i c h i s p r o d u c e d w h en s u c h a w a v e a c t s on t h e s p e c t i v e l y p i t c h and l o u d n e s s . " o f s o many d i v e r s e

e le m e n ts,

2

ear are r e ­

B e c a u se sp ea k in g c o n s i s t s

i t - i . s - d i f f i c u l t t o a n a ly z e th e

p r o c e s s b y w h ic h t h e v a r i o u s s o u n d s o f o u r l a n g u a g e a r e m a d e . D r . Edmund P r i n c e E o w l e r , J r . , M akes t h e f o l l o w i n g b r i e f summary: T h e r e a r e o n l y f i v e v o w e l s and 26 c o n s o n a n t s in th e E n g lis h la n g u a g e. Of c o u r s e , t h e r e a r e m ore t h a n f i v e v o w e l s o u n d s and m ore t h a n 26 c o n ­ s o n a n t s o u n d s , b u t f o r s i m p l i c i t y , l e t us n o t g o in to th a t. M ost o f t h e c o n s o n a n t s , e s p e c i a l l y t j i e s , t , b , p , and ch s o u n d s a r e h i g h l y p i t c h e d and r e l a t i v e l y w e a k , and a r e v e r y f r e q u e n t l y u s e d in E n g lish . T he v o w e l s t e n d t o b e l o w p i t c h e d and r e l a t i v e l y s t r o n g . T h a t i s why p a t i e n t s w i t h n o r m a l l o w t o n e h e a r i n g and h i g h t o n e l o s s e s com­ p l a i n t h a t t h e y can h ea r s p e e c h bu t ca n n o t un der­ s t a n d i t . . A f t e r a l l , i t i s t.he c o n s o n a n t s w h ic h

^ H. G. M o n tg o m e r y , " O p t i c a l C u rve A n a l y s i s , "B e l l £ a b o r a t o r i e s R e c o r d , 1 8 : 2 8 - 3 0 , S ep tem b er, 1 9 3 9 . 2 J o s e p h G. S t e i n b e r g , " I s Time Out o f T u n e ," B e l l L a b o r a to r ie s R ecord, 2 : 1 5 4 - 1 5 7 ,.J u ly , 1926.

make t h e m a j o r d i f f e r e n t i a t i o n

.

m w o r d s .”

L

H ow ever, F l e t c h e r g o e s f a r t h e r i n t o d e t a i l i n e x p l a i n ­ in g th e p r o c e s s . s i t io n a ls,

The p a r e v o w e l s , t h e d i p h t h o n g s , t h e t r a n ­

and s e m i - v o w e l s a r e p r o d u c e d b y t h e

•ess. o f sp ee c h : a tr a in

o r d in a r y proa-

~”The v i b r a t i o n o f t h e s e v o c a l p a s s a g e s s t a r t s

o f so u n d w a v e s w h ic h p a s s t h r o u g h t h e v o c a l p a s s a g e s

and i m p r e s s on i t

c e r ta in reson an t c h a r a c t e r is t ic s so th a t

th e v ib r a tio n s f i n a l l y

e m e r g e f r o m t h e m o u tn a s s p e e c h s o u n d s .

T he u n v o i c e d c o n s o n a n t s a r e fo r m e d b y a i r p a s s i n g t h r o u g h t h e s m a l l o p e n i n g s or o v e r s h a r p e d g e s i n t h e m o u th . T he v o i c e d c o n s o n a n t s a r e p r o d u c e d b y t h o s e tw o m e t h o d s com­ b in e d .

The l a n g u a g e i s

1) p u re v o w e ls ; sounds; tiv e

i,

ou,

o i,

co n so n a n ts, f ,

th e a ir o u t le t . th e

a, e,

5)

ew .

i,

d iv id e d a c co r d in g t o o, u.

2}

d ip h th o n g s,

lo n g v o w e l

3) t r a n s i t i o n a l s ; w, y , h .

4)

fr ic a ­

v , made b y r u s h i n g so u n d o f b r e a t h t h r o u g h se m i-v o w e ls;

1 , ;r, m, n , n g ,

v o c a l cord s p a r t i a l l y b lo c k e d .

n a n ts; b , p , d, t ,

sound a s f o l l o w s :

j,

6)

s o u n d s fr o m

sto p f r i c a t i v e

conso-

c h , g , k , made s i m i l a r t o f r i c a t i v e .

3

1 P a u l E . S a b i n e , .**On E s t i m a t i n g t h e P e r c e n t a g e L o s s o f U s e f u l H e a r i n g . ” T r a n s a c t i o n s o f t h e A m e r ic a n A cadem y o f Oph­ t h a l m o l o g y and O t o l a r y n g o l o g y . 1P . 1 9 0 , M a r c h - A p r i l , 1 9 4 2 . s H a r v e y F l e t c h e r , S p e e c h and H e a r i n g . D . Tan H o s t r a n d Company, 1 9 2 9 ) , p . 5 .

(Hew Y ork :

70 T h ose w it h im p a ire d h e a r in g d e v e lo p v o i c e im p e r f e c ­ t i o n s a c c o r d i n g t o t h e d e g r e e and t y p e o f h e a r i n g i m p a i r m e n t . T h o s e w i t h m i d d l e - e a r d e a f n e s s a r e a b l e t o h e a r and c r i t i c i z e th e

q u a l i t y and p r o n u n c i a t i o n o f t h e i r

much t o

own v o i c e s ,

p reven t d e t e r io r a t io n of sp eech .

and may do

H ow ever, th e

lo u d ­

n e s s o f one's own " v o ic e , o r t h e v o i c e s o f o t h e r s , a s w e l l a s l o u d n o i s e s a r e n o t h e a r d a s l o u d l y a s t h e y a c t u a l l y so u n d t o th e

o n e w i t h n o r m a l h e a r i n g a c u i t y when t h e r e i s

a m id d le e a r

im p a irm e n t. The p e r s o n s u f f e r i n g fr o m n e r v e d e a f n e s s may b e a f f e c t >ed i n a t l e a s t

t h r e e d i f f e r e n t w a y s d e p e n d i n g on w h e t h e r o r

n o t t h e im p a ir m e n t i s who i s

p a r tia l,

very severe,

p a r t i a l l y a f f e c t e d m ay h e a r h i s

v o ic e s n a t u r a lly , but not a s lo u d ly . a ffe c te d fin d

it

or t o t a l .

own and o t h e r p e o p l e ’ s T h o s e who a r e s e v e r e l y

in c r e a sin g ly d i f f i c u lt

to

v o i c e w h i l e t h o s e who a r e t o t a l l y d e a f f i n d

h e a r t h e i r own it

h e a r t h e i r own v o i c e s u n d e r a n y c i r c u m s t a n c e s .

im p o ssib le

2

, and a r e t h e o n e s w h ic h a r e f i r s t

d ea fn ess.

sh , f , th ,

a ffe c te d by nerve

F a ilu r e t o hear co n so n a n ts r e s u l t s in f a i l u r e

p r o n o u n c e th e m c o r r e c t l y ,

to

The h i g h e s t .

n o te s in th e sp ee ch range a re such c o n so n a n ts a s s , and

One

to

an d g r a d u a l l y a l a r g e r p e r c e n t a g e

o f c o n s o n a n t s b e c o m e i n a u d i b l e or m i s p r o n o u n c e d ; v o w e l s a r e pronounced i n a c c u r a t e ly ,

and d i s c o r d a n t t o n e s g r a d u a l l y

71 a ffect

sp eech .

^

The c o n s o n a n t s a r e f i r s t

a ffe c te d in nerve d ea fn ess

b e c a u s e t h e y a r e h i g h e r i n f r e q u e n c y and w e a k e r i n i n t e n s i t y th a n are v o w e ls. th e r e s u l t s

D e a f n e s s may b e i m m e d i a t e l y r e c o g n i z e d b y

o f p u r e t o n e and a u d i o m e t e r t e s t s ,

e a r ly sta g e s ,

it

c a n n o t b e d e t e c t e d when v o i c e

t e s t s are g iv e n .

T h is i s

"Speech

no t w o w o r d s a r e a c o u s t i c a l l y e q u a l ­

l y heard b ecau se o f accen t

and i n f l e c t i o n , and d i f f e r e n c e s i n

s u b j e c t ’ s f a m i l i a r i t y w itjr t h e w o r d s ;

m ore e a s i l y

and v i i i s p e r

due t o t h e f o l l o w i n g f a c t s :

sou nd s v a r y i n fr e q u e n c y ;

th e

but in th e

vow el sou nd s are

r e c o g n i z e d t h a n a r e c o n s o n a n t s w h i c h a r e m ore im ­

p ortan t in th e in te r p r e ta tio n t i o n are la r g e f a c t o r s , or f l e e t i n g sounds i s

of th e w ord.

and f i n a l l y

im p o r t a n t '.

fro m b e in g a p e r f e c t t e s t .

F a t i g u e and a t t e n ­

d am p en ing b y o u t s i d e n o i s e

T hese f a c t o r s p r e v en t

sp eech

2

W it h t h e p e r f e c t i o n o f n u m e r o u s i n s t r u m e n t s and d e ­ v ic e s,

p a r t ic u la r ly th e

m eans o f c a l i b r a t i n g - i t ,

(1): c o n d e n s e r t r a n s m i t t e r and t h e (2)

t h e ’ vacuum t u b e w i t h t h e

c ir ­

c u i t a r r a n g e m e n t s f o r p r o d u c i n g a m p l i f i c a t i o n and e l e c t r i c a l

*** F e d e r a l S e c u r i t y A g e n c y , " R e h a b i l i t a t i o n o f t h e D e a f and H ard o f H e a r i n g . " M onograph o f t h e H . S . O f f i c e o f Edu­ c a t io n , F ebruary, 1941, pp. 2 8 -2 9 . r* i

*

" R o b e r t S o n n e n s c h e i n and Norman L e s h i n , " F u n c t i o n a l E x a m i n a t i o n o f ‘H e a r i n g , " A n n a l s o f O t o l a r y n g o l o g y , 2 6 : 1 6 4 - 1 8 4 , — '--N o v e m b e r, 1 9 3 7 . . . ~-------------------------

o sc illa tio n s, s ib le

and t h e

o ssc illo g r a p h ,

th e

a u d i o m e t e r m ak es p o s ­

t h e b e s t m e th o d we h a v e o f t e s t i n g

fo r lo sse s

cf h e a r in g

s p e e c h and s o u n d s . S i n c e t h e p o w er o f s p e e c h i s

s o v a r i a b l e ,• a c o u s t i c a l

and e l e c t r i c a l . e n g i n e e r s h a v e d e s i g n a t e d sc r ib e sity

it.

v a r io u s term s t o d e ­

B y m ean s o f a m p l i f y i n g , o r i n c r e a s i n g t h e

o f w eak s o u n d s , i t

is p o ssib le

t o m e a s u r e th e m , and b y

a m p l i f i c a t i o n , p e o p le h a v in g h e a r in g l o s s e s n o r m a l l y u n h e a r d o r w eak s o u n d s . a m p lific a tio n i s iw a tts

are a b le to hear

The s t r i k i n g f o r c e b e h i n d

c a l l e d p o w er o u t p u t .

of a c o u s t ic pow er.

in te n ­

S e le c tiv e

It

i s m easured i n m i l l ­

su p p r e ss io n i s

e d b y m ean s o f d i f f e r e n t t y p e s o f f i l t e r s .

a c c o m p lish

The l o w , m i d d l e ,

o r h i g h t o n e s may be p r e v e n t e d f r o m b e i n g h e a r d , and o t h e r s a r e i n c r e a s e d i n s o u n d , and s e l e c t i v e

a m p lific a tio n i s

secured

P r o p e r f i l t e r i n g r e d u c e s l o u d t o n e s and f a v o r s w eak o n e s t h e r e b y g i v i n g t h e p r o p e r . l e v e l o f a m p l i f i c a t i o n w here i t

is

n ecessary. For d i f f e r e n t

i n d i v i d u a l s , ~the s p e e c h pow er v a r i e s

a c c o r d in g to th e ty p e o f v o ic e , erage p erson ,

and t h e t r a i n e d

p a r t i c u la r ly t h a t of th e

speaker.

S y l l a b i c p o w er v a r i e s

m ore w i t h t h e e m p h a s is g i v e n t h a n w i t h t h e A v o w el i n an a c c e n t e d s y l l a b l e

av­

vow el sound u s e d .

has u s u a lly th r e e

or f o u r

t i m e s a s m uch p h o n e t i c p o w e r a s o n e i n an u n a c c e n t e d s y l l a b l e . By t h e m eth o d o f s u p p r e s s i o n ,

or by s o f t e n i n g lo u d

73

sounds a t v a r io u s f r e q u e n c i e s , it

and i n c r e a s i n g t h e f a i n t o n e s ,

i s p o s s ib le t o stu d y th e v a r io u s ty p e s o f d e a fn e s s .

p r e s sio n in th e

upper h a l f

of th e

th e i n t e l l i g i b i l i t y

of sp eech .

w ords are d i f f i c u l t

to r e c o g n iz e .

Sup­

sp eech range i n t e r f e r e s w ith

The v o i c e

i s a u d ib le , but

C o n s o n a n t s s u f f e r m ore t h a n

do t h e v o w e l s , b u t v o w e ls l o s e p a r t of t h e i r c h a r a c t e r i s t i c q u a lity .

S u p p r e s s io n above t h e 1000 c y c le l e a v e s sp e e c h o n ly

about f o r t y p er cent

in te llig ib le

s u p p r e s s io n b e lo w 1000 a f f e c t s

t o norm al l i s t e n e r s w h ile

in te llig ib ility

as sp ee ch i s heard w ith n i n e t y - f i v e

h a r d ly a t a l l

per c e n t a c c u ra c y .

T h is

e x p l a i n s why p e o p l e s u f f e r i n g f r o m h i g h t o n e d e a f n e s s can h a r d l y hear sp eech c o r r e c t ly . p a r t ant p a r t in th e in te llig ib ility b ility

p l i e d by tw ic e th e

c o n s o n a n t s p l a y su c h an im ­

u n d e r sta n d in g o f

of v o ic e t e s t s

of sp eech is

lo sse s

S in c e th e

is

I e q u a l s YC2 , o r !i n t e l l i g i ­

e q u a l t o t h e p e r c e n ta g e of v o w e ls m u l t i ­ co n so n a n ts.

T h ose s u f f e r i n g fro m u n ifo rm

can h e a r q u i t e a c c u r a t e l y i f

d e c ib e ls above th e th e th r e sh o ld

s p e e c h , t h e fo rm u la f o r

sp eech i s

about t h i r t y

t h r e s h o l d o f a u d i b i l i t s r w h ic h e x p l a i n s t h a t

o f h e a r in g i s

not n e c e s s a r ily th e th r e sh o ld f o r

speech. T h e r e i s m uch d i s c u s s i o n a t t h e in g th e r e l i a b i l i t y

of th e

I t h as been argued th a t test,

and i t

p r e s e n t tim e c o n c e r n ­

a u d io m ete r i n t h e t e s t i n g

th e a u d io m ete r t e s t

m ea su r es what t h e

is

o f sp eech .

a th r e sh o ld

ear cannot h ea r r a t h e r th an

74 w hat i t

can a c t u a l l y h e a r .

lo ss

n o t s e v e r e , and c o m p a r i s o n i s made o f th e w h i s p e r e d

is

Speech t e s t s

a r e h e l p f u l w hen h e a r in g

and. s p o k e n v o i c e w i t h t h e a u d i o m e t e r t e s t . tests,

it

is

i m p o s s i b l e t o m a i n t a i n th e

l e v e l of lo u d n e ss. b e r s , w ords,

A lso ,

due t o t h e

or s e n t e n c e s u se d ,

com p are t h e t e s t s ,

or to

it

secure th e

H ow ever,

v o i c e a t a u n ifo rm

d iffe r e n c e

is

in sp eech

in

t h e num­

im p o ssib le t o

same r e s u l t s

a c c u r a te ly

on t h e r e t e s t .

S i g n i f i c a n t r e m a r k s a r e made" b y Edmund P r i n c e F o w l e r in t h is

c o n n e c tio n : The o b j e c t i o n t h a t t h e p u r e t o n e a u d i o m e t e r i s n ot a tr u e c r i t e r i a fo r sp eech i s n ot b a s i c a l l y v a lid . The d i f f i c u l t y i s n o t w i t h t h e a u d io g r a m w h ic h i s a d m i t t e d l y a p r e c i s e m e a s u r e m e n t o f t h r e s h : . o l d , bu t w i t h i t s u s u a l m i s i n t e r p r e t a t i o n t h r o u g h t h e u n w arran ted p r a c t i c e o f a v e r a g in g t h e s p e e c h t o n e s , or m u l t i p l y i n g b y 0 . 8 and c a l l i n g t h e r e s u l t a p ercen ta g e. H e r e in l i e s th e f a l l a c y . A lth o u g h a t f i r s t th o u g h t' one m ig h t t h i n k i t w o u ld b e e a s i e r t o o b t a i n a p e r c e n t a g e b y t e s t i n g w i t h s p e e c h d i r e c t l y , c a r e f u l e x p e r i m e n t s sh o w s p e e c h t e s t s a r e v e r y u n r e l i a b l e ; t h e y may v a r y a s much a s 2 0 0 p e r c e n t i n d i s t a n c e e v e n w i t h t r a i n e d e x a m in er s. On t h e o t h e r h a n d , t h e a u d i o m e t e r i s known t o b e e x a c t , and o b s e r v a t i o n s made w i t h i t c a n be r e p e a t e d w i t h a c c u r a c y . It is th erefo re b e t t e r t o t e s t w i t h t h e a u d i o m e t e r and u s e t h i s d a ta to i n t e r p o la t e f o r th e c a p a c it y t o h ea r sp eech th a n i t i s t o use sp ee ch i t s e l f . 1 T h o s e who d i s a g r e e w i t h t h e

u se o f t h e a u d io m ete r in

t e s t i n g f o r sp e e c h c la im th a t t h e r e i s

1

a sc ie n tific

Edmund P r i n c e F o w l e r , lx > c . p i t . ,

e x p la r -

pp. 9 4 0 -9 41 .

ja a tio n a s to t h e

reason th a t

th e a u d io m e te r t e s t

t e s t th e c a p a c ity to hear sp eech . c o m p o site n erv e c o n s i s t i n g

second branch i s th e is

o n ly a f f e c t e d

The c o c h l e a r n e r v e i s

o f tw o m a in n e r v e s .

t r a n s m it s h ig h t o n e s , and th e le sse r

does not a

One p a r t

o th e r p a r t t h e lo w t o n e s .

of th e

The

tw o i n v u l n e r a b i l i t y and

a f t e r th e h ig h to n e

b r a n c h , and t h i s

to n e branch i s n e v e r a f f e c t e d a lo n e or a t f i r s t .

1

lo w

The a s ­

c e n d i n g b r a n c h g o e s t o t h e g a n g l i o n v e n t r a l e w h e r e memory i s sto red .

C o n se q u e n tly ,

it

is

n e c e s s a r y to

s t i m u l a t e memory

w it h w ords r a t h e r th a n w it h so u n d s a s the a u d io m ete r d o e s . The i n d i v i d u a l r e s p o n s e t o be fo r

sounds i s

n o t t h e sam e a s i t

w o u ld

s p e e c h w h e r e some a s s o c i a t i o n c a u s e s o t h e r a s s o c i a t i o n s

i n w h i c h memory i s

aroused.

As t h e a s c e n d i n g b r a n c h i s l e a r n u c l e u s o f t h e Organ o f

a p r o je c tio n in th e coch­

C o r ti,, i t

has been e stim a te d

t h a t th e f u n c t i o n a l l o s s o f h e a r in g o f th e organ o f C o r ti can be b a sed on a s tu d y o f h a ir c e l l s , g e n e r a lly r e s u lt s and l o s s lo ss.

lo ss

i n a l o s s o f h e a r i n g fr o m 60 t o 90 d e c i b e l s ,

o f e x te r n a l h a ir c e l l s

l e a d s t o a 20 t o 4 0 d e c i b e l

T he i n d i v i d u a l p s y c h i c , r e a c t i o n ,

r e je c tio n

o f in te r n a l h a ir c e l l s

o f t h e h e a r in g o f sounds i s

or th e u n co n sc io u s

a l s o an im p o r ta n t f a c ­

t o r i n m a k in g th e v a r io u s h e a r in g t e s t s .

i

■N . A s h e r t o n , ”The C o c h l e a r N e r v e and t h e V a s c u l a r T h e o r y o f N e r v e D e a f n e s s . ” - J o u r n a l o f L a r y n g o l o g y and O t o l o g y , 5 5 :5 3 1 -5 4 5 ;: D ecem ber, 1 9 4 0 .

M e n ta l d e v e lo p m e n t and s p e e c h d e v e l o p m e n t a r e l a r g e l y in te r d e p e n d e n t. reta rd

sp eech

k n o w led g e.

A slig h t

degree o f d ea fn ess in

c o m p r e h e n s i o n and t h e a c q u i s i t i o n o f s p e e c h and

E m o tio n a l e x p e r ie n c e i s a l s o l i m i t e d ,

u c a tio n a l e x p e r ie n c e of

th e

and t h e e d ­

c h i l d may b e r e t a r d e d fr o m t w o to

th ree y ea rs.

Good h e a r i n g i s ,

c e s s w h ic h i s

secondary to

is

c h i l d h o o d may

th e r e fo r e , a s o c ia liz in g pro­

in te llig e n c e .^

As t h e

organ of h e a r in g

one o f t h e m a in i n s t r u m e n t s b y w h i c h t h e s e n s e i m p r e s s i o n s

f r o m t h e o u t e r w o r l d r e a c h t h e m in d , d e f e c t i v e h e a r i n g r e s u l t s in d e fe c tiv e sp eech i s

sp ea k in g a s w e ll.* ' T e s t in g t h e c a p a c it y t o hear

m ore t h a n t e s t i n g t h e

c a p a c ity to hear f a m ilia r

t h o u g h t s and v o c a b u la r y , f o r h e a r in g i s p e r ie n c e as r e v e a le d by i n t e l l i g e n c e . is

not c o n sid e r e d u n le s s sp ee ch i s

th e r e su lt

N o r m a lly , h e a r in g l o s s

a ffected ,

i t h as a se r io u s p sy c h o lo g ic a l e f f e c t

of p a st e x ­

on t h e

b u t w hen i t

is,

in d iv id u a l.

It

h a s b een found t h a t h e a r in g h a s a s e r i o u s p s y c h o l o g ic a l on t h e i n d i v i d u a l .

effect

I t h a s b e e n e s t i m a t e d t h a t t h e r e a r e more

t h a n tw o a'nd a h a l f m i l l i o n h a r d o f h e a r i n g s c h o o l c h i l d r e n who a r e n o t c o n s p i c u o u s l y a f f l i c t e d , t h e y p r e sen ts

a s e r io u s e d u c a tio n a l,

and b e c a u s e t h e y a r e n o t , s o c ia l,

a n d e c o n o m ic prob lem

1 N o r t o n C a n f i e l d , tTThe T y p e o f D e a f n e s s W hich R e s p o n d s t o F i s t u l i z a t i o n o f t h e O t i t i c C a p su le ," A n n a ls o f O to lo g y , R h i n o l o g y , and L a r y n g o l o g y , 4 9 : 2 4 8 , M a rc h , 1 9 4 0 . s Hugo F r e y ,

lo c .

3i t .,

pp. 8 1 -9 9 .

. . a s th e

i m p a ir m e n t w i l l a f f e c t th e m s o c i a l l y

t i o n a l ly in .la te r l i f e

when i t

and v o c a ­

i s m ore d i f f i c u l t

t o make a d ­

ju stm en ts. C o n ce rn in g t h e

im p o rta n ce o f h e a r in g t o s te n o g r a p h y ,

E l e a n o r S k i m i n who h a s b e e n a n a u t h o r i t y o n s h o r t h a n d f o r y e a r s , made t h e to

fo llo w in g

com m ents i n a p e r s o n a l c o m m u n ic a t io n

th e w r it e r : The t i t l e o f y o u r t h e s i s i s a n i n t e r e s t i n g one. To be s u r e , h e a r i n g i s o n e o f t h e v i t a l e le m e n ts i n d o in g s u c c e s s f u l s te n o g r a p h ic w ork. I t i s q u i t e l i k e l y t h a t t e a c h e r s d o n ’t a l w a y s r e c o g n i z e h a r d o f h e a r i n g p u p i l s , so u n s u c c e s s ­ f u l w o r k m ig h t w e l l b e t h e r e s u l t o f t h i s p h y s i c a l d i f f i c u l t y w i t h o u t e i t h e r th e p u p i l o r t h e " t e a c h e r b e i n g aware o f i t .

I d o n ’ t know o f a n y r e s e a r c h on t h i s but i t sh o u ld be d on e. In sh o rth a n d , in g th e f i r s t

s p e c ia l a tte n tio n

few days to th e v o ic e

su b ject,

s h o u l d be g i v e n d u r ­

q u a litie s ,

e n u n c ia tio n ,

g e n e r a l m ann er o f s p e e c h a s w e l l a s t o t h e

c h o ic e o f words o f

each s tu d e n t.

s p e e c h s h o u l d be

tested

T h o s e s h o w i n g im p a irm e n t

in

im m e d ia te ly fo r d e f e c t i v e h e a r in g i f t h i s h a s n o t a l ­

r e a d y b e e n don e a s i t m ay be n e c e s s a r y t o e l i m i n a t e th em fr o m c la s s.

It

is

a ls o w e ll t o p o in t out in t h i s

c o n n e c tio n th a t

A. C. M a n n in g , ”The C h i l d H a n d ic a p p e d b y D e a f n e s s . ” P a m p h le t o f t h e W e s t e r n P e n n s y l v a n i a S c h o o l f o r t h e D e a f , P itts b u r g h , P e n n sy lv a n ia .

many s t u d e n t s s u f f e r fr o m h i g h t o n e l o s s e s , lo sse s a ffe c t

d iffic u lt

th ese

s p e e c h , t e a c h e r s s h o u l d n o t be p e r m i t t e d t o

t e a c h s h o r t h a n d a s t h e i r s p e e c h m ig h t w ord p a t t e r n s ,

and i f

co n fu se th e v a r io u s

and make t h e s t u d y o f s h o r t h a n d e x t r e m e l y

to lea r n .

I t h a s b een d em on strated th a t r ig h t

an d w r o n g d i c t a t i o n m i g h t c a u s e a v a r i a t i o n o f SO w o r d s p e r m i n u t e , 1 and t h i s m ig h t b e e v e n g r e a t e r i f

t h e t e a c h e r had

f a u lt y e n u n c ia tio n . The a n a l y t i c r e p e titio n

approach i s

of sou nd s.

th e y are t h e d i f f i c u l t

e ffe c tiv e ly

V o w el s o u n d s p r e s e n t d i f f i c u l t y , sounds t o p r e se n t

n i n g s t u d e n t s s h o u l d be t a u g h t t o sound b y v o c a l i z i n g th e d iffe r e n tia te v o w e ls,

used by o r a l fo r

on p a p e r , and b e g i n ­

adapt the

s p o k e n w ord t o

sou n d s t h a t t h e y h e a r .

T hey n e e d t o

th e t h r e e d i f f e r e n t k in d s o f sp ee ch sounds o f

d ip h th o n g s,

and c o n s § n a n t s f r o m t h e b e g i n n i n g .

As

some s t u d e n t s l a c k a u r a l a c u i t y and c a n n o t d i f f e r e n t i a t e b e ­ tw een t h e vo w el so u n d s,

i t may b e n e c e s s a r y t o e x a g g e r a t e

th e m u n t i l t h e s t u d e n t b e c o m e s f a m i l i a r w i t h t h e v a r i o u s vow el sou nd s. c o n ta in in g one

Long s o u n d s s h o u l d b e i n t r o d u c e d f i r s t ; v o w e l s h o u ld be d r i l l e d

w ords

upon b e f o r e o t h e r

v o w e l sou nd s are g i v e n . T h e d e v e lo p m e n t o f a k e e n p e r c e p t i o n o f word s e n s e w o u ld d o u b t l e s s im p r o v e s p e l l i n g , w o r k in g v o c a b u la r y , and g i v e

p r o d u c e a m ore a d e q u a t e

c o m p e t e n c e i n o r a l and w r i t t e n

e x p r e ssio n .

In h is

s tu d y , T u rse fou n d t h a t out o f 268 p u p i l s ,

t h a t t h e r e w a s a raw p o s i t i v e

c o r r e la tio n of

s c r i b i n g a b i l i t y and a c o m b in e d t e s t and v o c a b u la r y . 1 lis te n in g

.7 5 b etw een tr a n f

i n p h o n e t i c s , w ord s e n s e ,

T h i s w o u ld a l s o b e a p p a r e n t i n r e a d i n g and ~

c o m p re h e n sio n o f t h e s t u d e n t a s t h e r e i s

o f fr o m 3 2 5 t o 1 0 0 w o r d s p e r m i n u t e i n o r d i n a r y In su ch a sy m b o lic la n g u a g e a s sh o rth a n d i s ,

a v a r ia tio n

r e a d in g m a tte r

th is

v a r ia tio n

w o u ld b e p o s s i b l y m uch g r e a t e r t h a n w o u ld be c o n d i t i o n e d b y in d iv id u a l in t e llig e n c e ,

v o c a b u la r y k n o w led g e,

The l o u d n e s s o f d i c t a t i o n w o u ld a l s o g r a p h ic a b i l i t y . to

As t h e

th em .

im p r o v e s t e n o ­

ea r i s g e n e r a l l y a ccu stom ed to l i s t e n

lo u d c o m p e llin g so u n d s,

d .a l e f f o r t

and word s e n s e .

i s n ecessary to

it

ig n o r e s th e f a i n t

o n e s a s sp e ^ ~

c o n c e n t r a t e a t t e n t i o n and t o h e a r

B e c a u s e o f many i n t e r n a l and e x t e r n a l f a c t o r s w h i c h

in t e r f e r e w ith th e d e te c tio n o f sp eech ,

so u n d s w h ic h a re

j u s t a u d i b l e r a p i d l y a p p e a r and d i s a p p e a r f r o m c o n s c i o u s n e s s . I t h a s b e e n fo u n d t h a t

p e r f e c t h e a r in g of--sp eech i s

b l e a t th e a u d ib le r a n g e , fo r d e c ib e ls above th r e s h o ld .

T h is i s

o r d in a r y sp eech a t fo u r f e e t . age o f m isu n d e rsto o d w ard s,

b e st h e a r in g i s

J

a b o u t 50 o r 60

th e u su al in te n s ity

D ista n c e

of

in c r e a s e s th e p e r c e n t­

and t h e f a c t o r o f i n d i v i d u a l a d a p ­

t a t i o n becom es e x tr e m e ly im p o r ta n t, t o a d ju s t th e m se lv e s to

im p o ssi­

f o r some a r e b e t t e r a b l e

th e v a r io u s sou n d -stream s

1 P a u l L. T u r s e , L o p . o a t . ,

p.

307.

th an a re

oth ers.

T h ese f a c t o r s o f d is t a n c e

are o f p a r tic u la r

sig n ific a n c e

in

U nder o r d in a r y c o n d i t i o n s , to

co n cen tra te l i s t e n i n g

u te s a t a tim e ,

and t o

is

c a s e s o f h e a r in g im p a ir m e n t. it

is

e x tr em e ly d i f f i c u l t

t o t a l k m ore t h a n t w o o r t h r e e m in ­

convert in to w r itte n

a t a h ig h sp ee d o f d i c t a t i o n i s a b ility

and l o u d n e s s o f d i c t a t i o n

s h o r t h a n d s y m b o ls

e v e n m ore d i f f i c u l t .

a c q u i r e d s l o w l y and p a i n s t a k i n g l y ,

T h is

and i n c a s e s o f

h a r d o f h e a r i n g p u p i l s , t h e d i f f i c u l t y i s more g r e a t l y p r o ­ nounced.

T here i s

a g r e a t d isa g re em e n t

d ic ta tio n

and t r a n s c r i p t i o n .

In th e

in th e

sta te

stan d ard s of

o f C a lifo r n ia a lo n e

t h e d i c t a t i o n r a t e o f t h e j u n i o r c o l l e g e s v a r i e d fr o m 15 w o r d s p e r m in u te t o 45 w ords p e r m in u te , t h e v a r i a t i o n w a s fr o m 20 t o

60 w o r d s p e r m i n u t e . 1

A fte r s tu d e n ts le a r n to b e g in w r it in g s t r o k e s . fir st. lig h t

and on d i f f i c u l t m a t e r i a l ,

d i s t i n g u i s h so u n d s,, t h e y s h o u ld

C on son an ts a r e u s u a l l y in tr o d u c e d

T h e s e m ay be l e a r n e d i n p a i r s b y e m p h a s i z i n g t h e and h e a v y s o u n d s w i t h t h e

L a ter th e

lig h t

and h e a v y s t r o k e s .

v a r i o u s v o w e l and d i p h t h o n g s o u n d s m ay b e p r e s e n t e d .

V o w e ls may b e l e a r n e d i n p a i r s w i t h s e n t e n c e a i d s f o r remem­ b e r in g so u n d s t o h e lp i n t h e m em o r iza tio n p r o c e s s .

T h is

m e th o d p e r m i t s s e l f - a c t i v i t y w i t h h a b i t f o r m a t i o n .

D ic ta tio n

1 C a l i f o r n i a S t a t e D ep artm en t o f E d u c a t io n , B u reau o f B u s in e s s E d u c a tio h , A c h ie v e m e n t S ta n d a rd s in S e le c t e d H u b j e c t s ~ ~ in b u s i n e s s E d u c a t i o n i n C a l i f o r n i a J u n i o r C o l l e g e s , b u lle t in 3, 1940, pp. 9 -1 0 .

81

from th e v e r y b e g in n in g h e l p s t o p r in c ip le s

e sta b lish

v a r io u s sh orth an d

and g i v e s s t u d e n t s w o r t h w h i l e a c t i v i t y

in g p r o c e s s .

At th e

in th e le a r n ­

sam e t i m e , new p r i n c i p l e s a r e i n t r o d u c e d ,

fo rm er ones a re r e v ie w e d ,

and i n s t r u c t i o n i s

g iv en

on b o t h an

i n d i v i d u a l and c l a s s b a s i s . As t o s t e n o g r a p h i c p u b lish e d t e x t

ta to r

c o n c e r n in g t h e arrangem ent o f t h e

so t h a t t h e b e s t h e a r in g m ig h t be e f f e c t e d and s t e n o g r a p h e r .

o ffic e

fu r­

by b o t h d i c ­

D i c t a t i o n s h o u ld n e v e r be j u s t a h a b i t

-of r o u t i n e , b u t e a c h l e t t e r

or m essage d i c t a t e d

f r o m a number o f c a r e f u l p r i n c i p l e s w h i c h t h e ta k en in to

i n an un­

" S e c r e t a r i a l T r a in in g ," D r. B la c k s to n e g i v e s

a ccu ra te d e t a ils n itu r e

or s e c r e t a r i a l c o m p e t e n c y ,

c o n sid e r a tio n .

I f p o ssib le ,

sh o u ld r e s u l t

d ic ta to r has

th e d ic t a t io n

be c a r e f u l l y p la n n e d p r e v io u s t o g i v i n g i t

to

th e

sh o u ld

sten o g ra p h er.

A l l t h e d e t a i l s w h ic h a r e i n t h e c o r r e s p o n d e n c e f i l e

s h o u ld be

g i v e n to t h e s t e n o g r a p h e r r a t h e r th a n d i c t a t e d t o h e r s o t h a t h e r w o r k m ig h t b e m ore a c c u r a t e .

N e ith e r th e d ic t a t o r nor th e

ste n o g r a p h e r sh o u ld be in t e r r u p t e d

d u rin g th e

d i c t a t o r sh o u ld r e f r a i n from c o v e r in g h i s l i p s or c i g a r e t t e s b etw een th e m ,s o t h a t th e tfeem i f n e c e s s a r y .

The d i c t a t o r

p a c e b a c k and f o r t h

in th e o f f i c e ,

tr a c tio n s

o th e r th an th o s e

e f f i c i e n c y o f w h ic h t h e

d ic ta tio n .

The

or h o ld in g , c ig a r s

s t e n o g r a p h e r may r e a d

sh o u ld n o t m u tte r h i s w o rd s, or p erm it u n n e c e ssa r y d i s ­

c o n d u civ e to

em p lo y ee i s

th e b e st

c a p a b le .

ste n o g r a p h ic

82

C h ap ter 4 METHODS OP TESTING HEARING T h e r e a r e tw o e x a c t m e th o d s o f m e a s u r i n g h e a r i n g . a r e by t h e

T h ese

p u r e t o n e m e t h o d , w h i c h w h en a c c o m p a n ie d b y e l e c t r i ­

c a l a p p a r a t u s g i v e s t h e a u d i o m e t e r ; and a l s o t h e t e s t

fo r

sou nd s

o f sp eech u s u a lly - d e s ig n a t e d a s th e w h isp e r t e s t s and t h e v o ic e tests.

T hese t e s t s

tu r e o f any d e f e c t ta tiv e

tests

are g iv e n i n o rd er t o d eterm in e t h e n a ­

as w e ll as th e c a p a c ity of h e a r in g .

d e te r m in in g th e

th e w a tch , th e

v o ic e

Q u a n ti­

c a p a c ity o f h e a r in g are g iv e n by

and t h e w h i s p e r .

Q u a lita tiv e t e s t s fo r

d i a g n o s t i c p u r p o s e s a r e g i v e n b y t u n i n g f o r k s , m o n o c h o r d , and th e G a lto n w h i s t l e . T h e s e t e s t s w h ic h a r e g i v e n f o r n u m ero u s p u r p o s e s h a v e b e e n i n c r e a s i n g i n number a s w e l l a s i n i m p o r t a n c e .

Some o f

t h e r e a s o n s f o r g i v i n g th e m may be e n u m e r a t e d a s f o l l o w s : (1)

I n o r d e r t o make a d i f f e r e n t i a l d i a g n o s i s i n c a s e o f im p a ir e d h e a r in g .

(2)

In o rd er t o d e te r m in e t h e need o f h e a r in g a i d s , and i f fo u n d n e e d e d , t h e ty p e t o be p r e f e r r e d ,

(3 )

P o r t h e e x a m in a tio n o f s c h o o l c h ild r e n in o rd er t o e v a lu a te t h e i r a b i l i t y to f o llo w in s t r u c t io n , an d i f a d e f e c t i s d i s c o v e r e d , a s a h e l p i n d e ­ te r m in in g t h e prop er c l a s s i f i c a t i o n f o r e d u c a tio n .

**-' I r e n e R . E w in g and A. W, G, E w in g , The H a n d i c a p ' o f ' D e a f n e s s . (New Y o rk : L on gm an s, G reen and Company, 1 9 3 8 ; , p , 4 8 .

(4 )

For e x a m in a tio n o f p r e s c h o o l c h ild r e n t h e same r e a s o n s .

fo r

(5 )

I n o rd er t o d e ter m in e f i t n e s s f o r o ccu p a ­ t i o n s i n w h ic h g o o d h e a r i n g i s e s s e n t i a l .

(6 )

To d e t e r m i n e f i t n e s s f o r m i l i t a r y ■d u t y .

(7 )

As a g a g e o f , t h e e f f i c i e n c y o f a p a r t i c u l a r m e th o d o f t r e a t m e n t .

(8 )

For a e s t h e t i c

(9 )

F o r c o n s i d e r a t i o n s i n m a r r i a g e when t h e r e i s in c id e n c e of d e a fn e ss in th e fa m ily . 1

and s o c i a l r e a s o n s .

Many s t u d i e s h a v e b e e n m ade r e c e n t l y i n m e a s u r i n g h e a r in g by a i r and D r . V. 0 .

c o n d u ctio n p r o c e s s e s ,

and D r . N . A . W a tso n

K hu dsen c l a i m t h a t a s many o r m ore s o u n d s m i g h t

b e h e a r d by b o n e c o n d u c t i o n a s b y a i r th e r e s u lt s p h y sic a l

o f a h e a r in g t e s t

c o n d u c tio n .

c a n be d e t e r m i n e d ,

e x a m i n a t i o n and a n i n t i m a t e

s h o u ld be m a d e 'o n a p h y s i c a l ,

B efo re a ca refu l

stu d y o f th e in d iv id u a l

o to lo g ic a l,

p s y c h o l o g i c a l and

p e d a g o g ic a l b a s is . D r. G o ld s t e in s t a t e d t h a t t h e s e ed w i t h p s y c h o l o g i c a l t e s t s q u o tie n t,

lim ita tio n

tests

and m e a s u r e m e n t s ,

of h e a r in g c a p a c ity ,

ground o f d e a f n e s s , p h y s ic a l f i t n e s s , in g , t e s t s

sh o u ld be c o r r e l a t in te llig e n c e

h e r e d ita r y bach -

a m e n d a b ility t o t r a i n ­

o f v i s i o n , and o t h e r s e n s o r y e q u ip m e n t, m u scle

^ W a l t e r A . W e l l s , "Some P r a c t i c a l C o n s i d e r a t i o n s w i t h R e g a r d t o H e a r in g T e s t s , " A nnal s o f O t o l o g y , R h i n o i o g y , and L a r y n g o l o g y , 4 9 : 4 2 7 , J u n e , 1 9 4 0 . ~

84

c o o r d in a tio n , k in e s t h e t ic

r e a c tio n s,

and s e n s e o f r h y t h m . **-

I n o rd er t o d e ter m in e th e n a tu re o f a d e f e c t , f u n c t i o n a l tests

a r e g i v e n by w h ic h th e

a c u i t y or d e g r e e o f d e f e c t a s

w e l l a s th e t y p e o f d e f e c t m ay be d e te r m in e d . s t r u m e n t s u s e d m u st b e s t a n d a r d i z e d b y t h e tic s

and o t o l o g y .

T h ese t e s t s ,

The v a r i o u s i n ­

sc ie n c e

of acous­

b a s e d upon t h e p r i n c i p l e s o f

a n a to m y and p h y s i o l o g y w h ic h a r e n e c e s s a r y i n a d m i n i s t e r i n g , d e p e n d on : t h e

c o n d u c t i o n m edium t h r o u g h w h i c h t h e s o u n d w a v e s

p a ss a s th e a i r ,

bones of t h e s k u l l ,

o r w a t e r a s w e l l a s upon

t h e c o n d u c t io n and p e r c e p t i o n h e a r in g m ec h a n ism s. p r in c ip le s of p h y sic s,

it

is p o ssib le

T hrough t h e

to d iffe r e n tia te

the

m edium o f c o n d u c t i o n , a n d t h r o u g h t h e p h y s i o l o g i c a l f u n c t i o n ­ in g pow er o f t h e e a r , m ay be d e t e r m i n e d .

t h e im p a ir m e n t o f t h e h e a r i n g m e c h a n ism

F u n ctio n a l t e s t s

and c l i n i c a l d a t a a r e

n e c e s s a r y i n f i n d i n g o u t t h e t y p e and c h a r a c t e r o f d e a f n e s s as w e ll as i t s

o r ig in ,

degree,

and p r o g r e s s i v e t e n d e n c i e s .

2

THE YOICE i f

The v o i c e i s

t h e m o s t u n i v e r s a l medium o f

our e n v ir o n m e n t, and d e f e c t i v e o f im p a ir e d h e a r in g .

speech i s

C o n se q u e n tly ,

co n ta ct w ith

one o f t h e f i r s t

sig n s

q u a n t i t a t i v e and q u a l i t a t i v e

^ Max A. G o l d s t e i n , T he A c o u s t i c M ethod f o r t h e T r a i n i n g o f t h e D e a f and H ard o f He a r i ng Ch i I d J ( S t . L o u i s : The L aryngoscope P r e s s , 1 ^ 9 ) , p . 5 1 . 2 IbicU p. 109.

85 tests

a r e made f o r h e a r i n g s p e e c h .

in te n sity , iz e d .

and c h a r a c t e r , v o i c e t e s t s

H ence,

it

is

in t e s t i n g h e a r in g . w h ic h t e s t

th e

im p o ssib le t o

to

c a n n o t becom e s t a n d a r d ­

d e p e n d on s p e e c h t e s t s

Numerous v o i c e t e s t s

in te llig ib ility

of

b a s e d on many f a c t s c o n c e r n i n g t h e a lp h a b e t.

As v o i c e s v a r y i n p i t c h ,

W ith s e l e c t i v e

have been c o n str u c te d

sp eech . v o ic e

a m p lific a tio n ,

a lo n e

T h ese t e s t s and t h e

are

use o f th e

i t w i l l be p o s s i b l e

i n c r e a s e t h e weak s o u n d s s o t h a t t h e y may b e m e a s u r e d m ore

a c c u r a t e l y th an i n t h e p a s t . 1 P o l i t z e r a t t e m p t e d t o g r o u p s o u n d s o f h i g h , m i d d l e , and l o w t o n e s f o r a c u i t y and d i s t a n c e G-roup I

as fo llo w s:

(a)

H ig h -fr e q u e n c y and p e n e t r a t in g h i s s i n g s o u n d s : S , S h , and G s o r t .

(

The t o n a l r a n g e f o r t h e n o rm al e a r : S h -so u n d , 500 f e e t ; S - s o u n d , 475 f e e t ; G o r Ch, s o f t , 3 2 0 f e e t .

(b)

H i g h , w ea k F - s o u n d s : F a n d ' V. ra n g e o f F -s o u n d , 170 f e e t .

Group I I

T on e

E x p l o s i v e s o u n d s o f medium f r e q u e n c y : B -so u n d , K -sou n d , F -s o u n d . T o n a l ra n g e o f K -a n d -F -so u n d , 160 f e e t B - s o u n d , 55 f e e t .

Group I I I

Low s o u n d s : TJ, R l i n g u a l w i t h o u t v o i c e . Tone r a n g e : U (w h is p e r e d ) 125 f e e t ; to n e ra n g e R (sp o k e n a t t i p o f t o n g u e ) , 110 feet.

1 Max A . G o l d s t e i n ,

oj>* c j t . , p . 1 1 2 .

86

U, a s w e l l a s o th e r v o w e ls, i s o n ly s u it a b le i n w h is p e r e d sp ee ch f o r d i f f e r e n t i a l d i a g n o s i s . Mr. W a tso n b e l i e v e s t h a t s p e e c h t e s t s

-

s h o u l d make a d i s ­

t i n c t i o n b e t w e e n t h e l o w f r e q u e n c y v o w e l s a nd t h e m i d d l e f r e ­ q u e n c y l i q u i d s and n a s a l s

( 1 , r , w , m, n) and t h o s e f r o m t h e

h i g h f r e q u e n c y d e n t a l s and s p i r a n t s m an’ s v o i c e i s

(t; th , d,

s,

z).

The

u s u a l l y around 128 v i b r a t i o n s p e r s e c o n d ,

a wom an’ s a t 2 5 6 v i b r a t i o n s p e r s e c o n d .

and

The so u n d c o m p o n e n t s

b e t w e e n 5 0 0 and 3 0 0 0 c y c l e s on t h e a u d i o m e t e r a r e m o st im ­ p o rta n t in sp eech i n t e l l i g i b i l i t y . sp eech range:

v o w e l s and f u n d a m e n t a l s ,

l i q u i d s and n a s a l s and s p i r a n t s h ig h e r .

T h is i s

(s,

t,

(r,

1 , m, n )

p, th ,

im p o r ta n t

100 to 800 c y c l e s ;

500 t o 2 0 0 0 c y c l e s :

e tc .)

d e n ta ls

1 8 0 0 t o 3 0 0 0 c y c l e s and

s

The v o i c e t e s t s

in c lu d e th e

lo u d v o i c e , th e w h is p e r ,

an d t h e c a s u a l c o n v e r s a t i o n i n t e l l i g i b i l i t y test

th e

sen ten ces,

of

sp eech th rou gh

sta n d a r d iz e d s e n te n c e s , n on sen se s y l l a b l e s ,

and c a l l e d n u m b e r s .

The t e s t s

u sed m ost f r e q u e n t l y a r e t h o s e

c o m p i l e d b y F l e t c h e r and S t e i n b e r g o f t h e B e l l T e l e p h o n e Lab­ o r a to r ie s.

n

T he S h o r t I n t e l l i g i b i l i t y T e s t i n c l u d e d c a l l e d

Max A. G o l d s t e i n , X o c . c i t .

^ L. A . ‘W a t s o n , ’’A u d i o m e t e r s , H e a r in g A i d s , and t h e E a r S p e c i a l i s t . ” M onograph p u b l i s h e d b y t h e M a ic o Company, p . 158.

87

num bers, as 8 4 , ah* e r ,

ay,

65, 13,

ow, e t c . ,

w o r d s a s baw ,

22,

e tc.

and t h e

vaw , gaw , l a w ,

1

The v o w e l t e s t

in c lu d e d

consonant t e s t in c lu d e d su c h p e tc. A s a m p le o f t h e t e s t

se n te n c e s fo llo w : 1. 2. 3.

-Name a p r o m i n e n t m i l l i o n a i r e o f t h i s c o u n t r y ? How l a r g e i s t h e su n co m p a red w i t h t h e e a r t h ? Why a r e f l a g p o l e s su r m o u n te d b y l i g h t n i n g r o d s ? 3

D u r i n g v o i c e 1t e s t s , t h e and each to

ear t e s t e d

se p a r a te ly .

c o n c e n t r a t e on t h e

test,

b e s t t o m ash o n e e a r ,

or to

The f e m a l e v o i c e i s th e m a le .

wom an’ s . th e f a c t

The s u b j e c t

s h o u l d b e made

and s o m e t im e s i t c lo s e i t

ways w h ile th e o t h e r e a r i s

is

s u b j e c t ’ s e y e s sh o u ld be c l o s e d ,

to

h a s b e e n fo u n d

sound s by v a r io u s

b e in g t e s t e d .

b e t t e r u n d ersto o d a s a r u le th a n

The m a n ’ s v o i c e

is

lo w er i n p it c h

th an i s th e

’’T h e d i f f e r e n c e b e t w e e n t h e two v o i c e s i s

due t o

t h a t t h e m an’ s h a s tw o l a r g e l o w - p i t c h e d c o m p o n e n t s ,

on e o f 1 2 8 and one

o f 256 v i b r a t i o n s p e r s e c o n d , w h ile th e

wom an’ s h a s on e ( l a r g e r ) b r a tio n s per secon d.

o f 2 5 6 and o n e ( s m a l l e r )

The s i m i l a r i t y b e tw e e n t h e

v o w e l ” e e ” a s u t t e r e d b y t h e s e tw o v o i c e s , w h i c h c a u s e s t h e l i s t e n e r t o know t h a t

it

th e is

E w in g

andE w in g ,

op . c i t . , p. 322.

2 E w in g

and E w in g ,

o p .c i t . ,

p. 323.

3 E w in g

and E w ing ,

o p .c i t . ,

p . 132.

o f 512 v i ­ sound o f t h e

sim ila r ity

i n d e e d ” e e ” and

88 n o o t h e r v o w e l w h i c h h a s b e e n s a i d or s u n g ,

c o n sists of a

s m a l l g r o u p o f h i g h - p i t c h e d c o m p o n e n t s common t o b o t h . p itc h

o f t h e s e c o m p o n e n ts i s

The

b e t w e e n 2 0 0 0 and 2 4 0 0 v i b r a t i o n s

p e r s e c o n d . **I n c a s e s o f som e t y p e s o f n e r v e d e a f n e s s , v o ic e is b etter ter

b etter

t h e m a le

u n d e r s t o o d ; f a m i l i a r w o r d s and p h r a s e s a r e

u n d e r s t o o d t h a n u n f a m i l i a r , and m u s i c a l n o t e s a r e b e t ­

heard th a n i s

sp eech .

When t e s t i n g w i t h t h e w h i s p e r e d

v o i c e , t h e r e s i d u a l a i r i n th e lu n g s sh o u ld be u se d . im p o ssib le

fo r

sp ea k er s to m a in ta in th e

are o f o n ly r e l a t i v e v o ic e

v a lu e .

i s a b o u t 80 f e e t .

sta n t

change th e

T h is i s

same t o n e , t h e s e t e s t s

ex p ressed as 8 0 /8 0 . 4 0 /2 0 .

n u m era to r, but th e

in b oth c a s e s a s i t

is

N orm al h e a r i n g f o r c o n v e r s a t i o n a l

p e r e d v o i c e f o r th e norm al e a r i s n o rm a l,

As i t

The w h i s ­

D e v i a t i o n s from t h e

d en o m in a to r r e m a in s c o n ­

e x p r e s s e s th e h e a r in g f o r th e norm al

ear. 2 One o f t h e b e s t m e th o d s o f v o i c e t e s t i n g graph as i t

m ak es i t

p o ssib le

to reproduce th e

is

v o ic e

th e phono­ a t an e v e n

l e v e l w h ic h c a n be r e p e a t e d a t d i f f e r e n t d a t e s u n d e r t h e sam e te s tin g

c o n d itio n s.

N e v e r th e le ss ,

sp e e c h sou n d s v a r y i n f r e ­

q u e n c y a s no tw o w o r d s a r e a c o u s t i c a l l y e q u a l l y h e a r d b e c a u s e o f a ccen t of i n f l e c t io n , fa m ilia r ity

w ith th e

and d i f f e r e n c e s i n t h e

w ords.

V o w e ls a r e m ore e a s i l y

S w in g and E w i n g , o p . c i t . , ^ .G o ld ste in ,

o td

.

c i t .,

lis t e n e r ’s

p.

p.

114.

51.

r e c o g n iz e d

89 b u t c o n s o n a n t s a r e m ore n e c e s s a r y w ords. a lso

F a tig u e , a t t e n t io n , im p o rta n t.

in th e in t e r p r e t a tio n of

and dam p en ing b y o u t s i d e n o i s e

The t e s t i n g

o f h e a r in g

s p e e c h b y th e p h o n o ­

graph i s n e c e ssa r y in th e stu d y of d e a fn e ss as i t th e d eg ree of h e a r in g l o s s . in d e ter m in in g a v o ic e

^

" W h ile t h e r e

stan d ard ,

v o ic e

is

d e te r m in e s

are im p e r fe c tio n s

tests

are n e v e r t h e le s s

i n d i s p e n s a b l e i n t h e e s t i m a t i n g o f h e a r i n g d e f e c t s and a l s o i n d e te r m in in g r e s u l t s in a g iv e n c a se ."

o f a n y t r e a t m e n t t h a t m ay b e a p p l i e d

^ WATCH TEST

W a t c h e s v a r y i n p i t c h and i n t e n s i t y ly r e lia b le .

The s t a n d a r d g e n e r a l l y u s e d i s

f o r th e p ock et w a tch . i n c h e s h e ld from t h e

c lie n t,

I f t h e w atch i s

h e a r d by a i r

r e c o r d e d a s 6 0 /6 0

The n u m e r a t o r i n d i c a t e s

a t w h ic h h e p e r c e i v e s t h e sta n t.

and a r e n o t a b s o l u t e

t h e number o f

and may v a r y w i t h t h e d i s t a n c e

sou nd .

h e ld a t

c o n d u ctio n , but i f

The d e n o m i n a t o r r e m a i n s c o n ­ arm ’ s l e n g t h , t h e it

i s p ressed to

sound i s th e head, i t

i s h e a r d b y bon e c o n d u c t i o n .

pp.

R o b e r t S o n n e n s c h e i n a n d Norman L e s h i n , 17 7 -1 7 8 . ^ G o ld ste in ,

op. c i t .,

pp.

1 1 6 -1 1 7 .

op.

c it. ,

THE ACOUMETER The a c o u m e t e r ,

c o n s tr u c te d by P o l i t z e r ,

m ent w h ic h p r o d u c e s ' a n o i s e w a tch , th e d ista n c e

p itc h

of

tic k

an i n s t r u ­

o f a lo u d

w h ic h w as h e a r d b y t h e n o r m a l e a r a t a

of fo r ty -fiv e

u t e s t f o r b o th a ir

s im ila r to th e

is

feet.

T h is w as

c a lib r a te d

so as to

and b o n e c o n d u c t i o n a c u i t y . TUNING FORKS

The t u n i n g f o r k s t e s t f o r t h e p h y sic s i f d iffe r e n t

p u r e s t t o n e known i n

th e y are p r o p e r ly c o n str u c te d .

T u n in g f o r k s o f

p it c h e s are arranged in s e r i e s ;

t h e y a re used to

f i n d t h e r a n g e o f h e a r i n g t h r o u g h o u t t h e m u s i c a l s c a l e fr o m 16 t o 4 0 9 6 v i b r a t i o n s ; lo sse s;

t o d e ter m in e th e

a ly z e th e and, to

to a s c e r ta in a ir

and b o n e c o n d u c t i o n

s ig n ific a n c e of th e lo s s e s ;

c o m p lete t o n e s c a l e t o

fin d

isla n d s

an­

of d e a fn e s s ,

s t a r t a n i n d i v i d u a l r e c o r d o f im p a ir m e n t

a f t e r treatm en t has begun.

to

b e f o r e and

1

A l t h o u g h t h e r e a r e many a d v a n t a g e s c l a i m e d f o r t h e fu n c tio n a l t e s t s

o f tu n in g f o r k s ,

w i d e l y u s e d b y many o t o l o g i s t s ,

and a l t h o u g h t h e y a r e s t i l l

t h e y a l s o h a v e many I m i t a t i o n s .

T hey ca n n o t d e t e c t d i f f i c u l t t y p e s o f r e s i d u a l h e a r in g i n t h e c o n g e n ita lly deaf or in

c e r ta in ty p e s of a d v e n titio u s d e a fn e ss.

One o f t h e m o s t i m p o r t a n t o f t h e s e t e s t s test.

T h is t e s t

tu n in g fo r h i s c o n d u c tio n .

is

c o n sid e r e d p o s i t i v e

heard tw ic e

I f th e

(-}.

i f th e

a ir

t h e R h in n e so u n d in g

a s lo n g by a i r c o n d u c tio n a s by bone

c o n d u c tio n a p p a ra tu s o n ly i s

c o n d u ctio n in c r e a s e s , i s n e g a tiv e

(/)

is

c o n d u c tio n d e c r e a s e s ,

a ffected ,

and t h e r e s u l t

When t h e p e r c e p t i v e a p p a r a t u s o n l y i s

b o t h a i r and b o n e c o n d u c t i v i t y d e c r e a s e s and t h e r e s u l t o r R in n e p o s i t i v e .

When t h e

so u n d i s

im p a ir e d is

(N /),

co n d u cted e n t i r e l y by

bone c o n d u c t io n o v e r th e m a s t o id p r o c e s s e s , t h e r e s u l t corded as

bone

is

re­

(ab s R - ) .

Two f a c t o r s e l i m i n a t e d by th e

o f e r r o r i n t h e s t a n d a r d R in n e t e s t

c a n be

u se of th e a u d io m ete r:

(1 )

The e r r o r du e t o t h e c o n s t a n t d e c r e m e n t o f t h e f o r k and t h e i n t e n s i t y o f t h e t o n e u s e d w i t h th e a u d io m ete r f o r b o th b on e and a i r c o n d u c tio n rem a in s f i x e d f o r e a ch s e t t i n g of t h e a u d io m e te r in te n sity d ia l.

(2 )

The e r r o r d u e t o p o s s i b l e v a r i a t i o n s i n p r e s s u r e and i n t h e s e l e c t i o n o f t h e p o i n t o f c o n t a c t a g a in s t t h e m a sto id p r o c e s s i s e lim in a te d b eca u se i t i s p o s s ib le t o m a in ta in th e t o t a l i n t e n s i t y w h i l e t h e p r e s s u r e v a r ie d a t w i l l or w h i l e t h e optim um p o i n t o f c o n t a c t i s b e i n g l o c a t e d . W eber t u n i n g f o r k t e s t

t h r o u g h bone c o n d u c t io n . th e tu n in g fo r k i s

is

a b ila t e r a l r a d ia tio n

The Schw a b a c h t e s t

is

o n e i n w h ic h

p la c e d i n t h e m id d le o f th e m a s to id ; t h e

0. G. B u n c h , ”The R in n e T e s t a n d t h e A u d i o m e t e r . A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 5 0 : 5 4 , March 1 9 4 1 /' ~

92 n o r m a l e a r v a i l h e a r t h e s o u n d 20 s e c o n d s i f w h ile

th e im p a ire d e a r h e a r s i t

a c o n d u c tiv e d e a f n e s s , im p a irm e n t.

it

f o r 30 s e c o n d s i f t h e r e

o r fr o m 1 0 t o 1 5 i f

th ere

o f tu n in g fo r k t e s t s

fo o tp la te test

is

is

a nerve

The d r a w b a ck i s t h a t t h e t u n i n g f o r k may n o t a l ­

w a y s be s t i m u l a t e d t o t h e sam e t o n e i n t e n s i t y .

G e lle t e s t

i s norm al

is

a r e t h e G -elle and t h e B i n g t e s t .

one f o r th e t e s t i n g

of th e

O th e r t y p e s The

o f th e m o b i l it y o f th e

s t a p e s i n t h e o v a l w in d o w w h i l e t h e B i n g

d e ter m in e s th e p o s i t i o n o f t h e E u sta c h ia n tu b e .

^

THE GALT ON WHISTLE T he G a l t o n W h i s t l e t e s t s t h e I t w as m o d i f i e d

b y E d e lm a n n , and t h e b e s t i n s t r u m e n t

G a lt o n - E d e lm a n n w h i s t l e . o f th e w h is tle in an d i t

is

h ig h e r m u sic a l t o n e s .

its

T here i s

i s th e

a d e fe c t in t h e p e r c e p tio n

s c a l e from 4 ,0 0 0 t o 2 5 ,0 0 0 d e c i b e l s ,

not a lt o g e t h e r r e l i a b l e . THE M0N0CH0RD

To o v e r c o m e t h e e r r o r s o f t h e G a l t o n w h i s t l e , d e v i s e d th e M onochord. fla t

o f a 60 cm.

s t e e l b a r on w h i c h a s t e e l w i r e w i t h a n a d j u s t a b l e

screw i s is

The M onochord c o n s i s t s

S tru y ck en

stru n g t o

d e fin ite te n sio n .

The t e n s i o n

set­

o f th e w ir e

a c c u r a t e l y m e a s u r e d b y a s i m p l e c o n t r o l d e v i c e b y m eans

^ Loc. cit.

93 o f w h ic h a f i x e d in str u m e n t.

s t a n d a r d o f t o n e may be o b t a i n e d w i t h e a c h

S c h a e f e r m o d i f i e d t h e m o n o ch o rd f o r t r a n s v e r s e

v i b r a t i o n s and a d d ed a t e n s i o n

c o n tr o lle r to i t .

1

OTSTAGMJ8 TEST The n y s t a g m u s t e s t u n d e r two y e a r s o f a g e . s tim u la tio n o f th e c a n a ls.

is

The n ystagm u s i s

a c co m p lish ed by

v e s tib u la r nerve in th e

When a s m a l l c h i l d

and r o t a t e d ,

used f o r t e s t i n g s m a ll c h ild r e n

or when h e i s

is

se m i-c ir c u la r

p la c e d in a r e v o lv in g c h a ir

su b je c te d to th e e f f e c t s

in g t h e e a r w it h h o t o r c o ld w a te r ,

o f douch­

th e c h ild w i l l m a n ife st

a n y stagm u s o r s t i m u l a t i o n o f t h e s t a t i c

la b y r in th .

THE CONDITIONED REFLEX T he c o n d i t i o n e d r e f l e x h a s b e e n u s e d i n e x p e r i m e n t a l p sy c h o lo g y in th e t e s t i n g

o f c h i l d r e n under t h r e e y e a r s o f

age as i t

t e s t th e m b y o t h e r m e t h o d s .

is

d iffic u lt

to

c o n d itio n e d resp o n se has th e in c h ild r e n a s in a n im a ls, and s o u n d i n f l u e n c e

same m e c h a n is m o f d e v e lo p m e n t

and t h e e x t e r n a l s t i m u l i o f s i g h t

th e r e sp o n se .

v a r io u s w ays, but t h e in f lu e n c e

T h i s t e s t may b e g i v e n

0£

.

c i t .,

in

of th e e x te r n a l stim u li cau ses

t h i s t o b e an u n c o n t r o l l e d m e th o d o f t e s t i n g .

**- G o l d s t e i n ,

The

p. 135.

94 THE AUDIOMETER T he h i s t o r y o f t h e m o s t s c i e n t i f i c ,

a ccu ra te,

e ffe c tiv e ,

and s t a n d a r d i z e d m e a n s o f t e s t i n g h e a r i n g a t t h e p r e s e n t t i m e i s t h e a u d i o m e t e r w h ic h i s in r a d io ,

tele p h o n e ,

th e r e s u lt

and a c o u s t i c a l l a b o r a t o r i e s .

in v e n tio n of th e te le p h o n e , th e The a p p l i c a t i o n o f t h e h e a r in g t e s t s 1879.

- W it h t h e

a u d io m ete r o r i g i n a t e d i n 1 8 7 6 .

e le c tr ic

c u r r e n t was a p p l ie d t o

i n 1 8 7 8 b y A. H a rtm a n , a n d by D . E . H u g h es i n

Many s c i e n t i s t s

c h in e .

of e x te n siv e resea rch

c o r r e c t e d v a r i o u s d e f e c t s i n t h e ma­

Some o f t h e m o s t s i g n i f i c a n t c o n t r i b u t i o n s may b e a t ­

t r i b u t e d t o L a c h a r r ie r e and P a r i s i n 1 8 8 2 , t o U r b a n t s c h it s c h i n 1 8 8 4 , who d e s c r i b e d h i s e l e c t r i c th e

c o n t r ib u t io n s . o f G o zo lin o ,

1 8 9 5 ; T r e t o p , 1908,* G r a d e n i g o , 1916.

a co u m eter. 1

1895;

C h ev a l,

la te r

1890; Jacob son ,

1907; S e a sh o re ,

1 8 9 9 ; and F o y ,

In 1 8 9 8 , B e z o ld used a c o n tin u o u s to n e s e r i e s

in g fo r k s fo r t e s t i n g , b y O stm an n .

In 1914,

came

o f tu n ­

and i n 1 9 0 5 , t h e s e had b e e n p e r f e c t e d S t e f a n n i u s e d an e l e c t r i c a l g e n e r a t o r

w h ic h w o u ld p r o d u c e a n a l t e r n a t i n g

cu rren t w ith a range o f

f r e q u e n c ie s con d u cted by a te le p h o n e r e c e i v e r .

^ G o ld ste in , 2

o jd

.

c i t . , p.

135.

G. C. B u n c h , ,rT he ■D e v e lo p m e n t o f t h e A u d i o m e t e r . ” L a r y n g o s c o p e , 5 1 :1 1 0 0 - 1 1 1 6 , D ecem ber, 1 9 4 1 .

The r e a l b e g i n n i n g o f s c i e n t i f i c

te s tin g

s ta r te d w ith

t h e i n v e n t i o n o f D r . L ee W a l l a c e D e a n and G o r d ia C. B u n c h , c o o p e r a t i n g w i t h P r o f e s s o r C a r l E . S e a s h o r e * who p u b l i s h e d i n th e L a r y n g o sc o p e , A u g u st,

1 9 1 9 , p p . 4 5 3-462*

t h e P i t c h R a n g e'A u d io m ete r i n O t o l o g y . "

HTbe U s e o f

I n 1 9 2 1 , D r. John

G uttm an p r e s e n t e d b e f o r e t h e S e c t i o n o n O t o l o g y , New y o r k Academy o f M e d i c i n e ,

and p u b l i s h e d i n t h e L a r y n g o s c o p e , D e­

cem ber, 1 9 2 1 , p p . 9 6 0 -9 6 4 ,

"A New M ethod o f M e a s u r i n g Pow er

b y M eans o f t h e E l e c t r i c A c u a le t e r ." I n 1 9 2 2 , t h e W e s t e r n E l e c t r i c A - l A u d io m e t e r w a s p r o ­ d u c e d b y E o w l e r and W e g e l and t h e phone l a b o r a t o r i e s .

e n g in e e r s o f t h e B e ll T e le ­

D u r i n g t h e same y e a r , H a s t i n g s and T u c k e r

p r o d u c e d t h e Vacuum t u b e s e t , w h i c h w as a t y p e o f p h o n o g r a p h e m p lo y in g t h e

u s e o f s p o k e n nu m b ers i n t h e t e s t i n g .

K nudson and J o n e s , pany,

u n d e r t h e s p o n s o r s h i p o f t h e S o n o t o n e Com­

c o n t r i b u t e d t h e vacuum t u b e s e t t o

and i n 1 9 2 4 ,

In 1924,

sc ie n tific

te s tin g ,

t h e K ran z a u d i o m e t e r w a s made a v a i l a b l e .

The 3-A A u d i o m e t e r w as d e v e l o p e d i n o r d e r t o th e w atch or t h e

a c o u m e t e r f o r m a k in g q u i c k t e s t s .

m uch m ore a c c u r a t e and r e l i a b l e

th an i s

th e w a tch ,

not r e q u ir e th e o p e r a tio n o f s p e c i a l i s t s . c o m b in e d t o n e c o v e r i n g t h e b a t t e r y and i s p o r t a b l e .

sp eech range.

r e p la c e It

is

and d o e s

I t has a s in g le It

is

The 3-A and 5 -A t e s t s

o p e r a te d by are g e n e r a lly

96 used in s t e a d

o f th e 4-A .

th r e e m in u te s or l e s s ,

The t e s t

u s u a l l y r e q u i r e s tw o o r

a n d t e s t i n g m u s t be d on e i n a v e r y

q u i e t room . T he 4 -A A u d i o m e t e r i s L a b o r a to r ie s.

It

is

a g r o u p t e s t m a k in g p o s s i b l e t h e exam ­

in a tio n of f o r t y p erson s a t m in u te s t o g i v e . fo rty ,

a tim e r e q u ir in g n ot o v er tw e n ty

T he p r e f e r r e d number o f c h i l d r e n t e s t e d

as th e t e s t in g

fic a tio n ,

a p r o d u c t o f th e B e l l T e le p h o n e

o f more t h a n f o r t y

s im ila r t o a phonograph, th e

4 -A P h o n o g r a p h A u d io m e t e r h a s t e l e p h o n e be d i s t r i b u t e d

record s.

a m p li­

and c h a n g e s t h e t h r e s h o l d o f t h e t e s t .

B e in g c o n s t r u c t e d q u it e

c o n sists

c u t s down t h e

is

r e c e i v e r s w h i c h may

t o ea ch o f th o s e b e in g t e s t e d .

The a p p a r a t u s

o f a n o r d in a r y ph on ograp h t u r n t a b l e w h ic h u s e s d i s c A n e e d le r e c e iv e s th e

so u n d and a m a g n e t i c p i c k - u p

fu r n ish e s th e n ecessa ry e l e c t r i c i t y

fo r th e

tr a n sm issio n o f

t h e sounds t o t h e e a r p h o n e s. T he 4 -A P h o n o g r a p h A u d i o m e t e r t e s t . i s te s tin g sch ool c h ild r e n .A

S p e c i a l r e c o r d form i s

e a c h p e r s o n under e x a m in a tio n . th ree d ig it s t o be t e s t e d .

a re u se d d e p e n d in g on t h e a g e s o f th e P u p ils are g iv e n

in str u c tio n s,

g iv en t o

p u p ils

and t h e y w r i t e The t e s t s

o f tw o c o lu m n s o f n u m b ers h e a r d by t h e v o i c e

Loc. cit.

used in

Num bers o f e i t h e r two or

t h e nu m bers w h ic h t h e y h e a r i n f o u r c o lu m n s . sists

o ften

con­

o f th e

97 man wlio c a l l s t h e

n u m b e r s , and a l s o tw o c o lu m n s f o r t h e

wo­

m an’ s v o i c e . "The v o i c e s a r e g r a d u a l l y dam pened t h r e e s e n s a t i o n u n i t s a t a t i m e so t h a t t h e n u m b ers a r e l e s s heard t i l l

a p o in t i s

The s e c o n d c o lu m n i s

r e a c h e d w hen t h e c h i l d h e a r s no nu m ber. th en

a n n o u n c e d and s t a r t e d .

um ns, t w o i n t h e m a n ’ s v o i c e c o n stitu te

th e t e s t

fo r

su pp osed t o a llo w f o r

and l e s s r e a d i l y

Four c o l ­

and tw o i n t h e wom an’ s v o i c e ,

each e a r .

T h e s e f o u r c o lu m n s a r e

e x tra n eo u s n o is e s

and u n f a m i l i a r i t y

w i t h t h e t e s t . ’1 ^ The r e c o r d s made b y e a c h may be m ark ed q u i c k l y w i t h a m a ster s h e e t ,

and t h e p u p i l i s

umn r e c o r d e d i n T he l a s t

g iv en c r e d it

se n s a tio n u n it s ,

fo r th e

b est c o l­

r a n g i n g fr o m 30 t o m in u s 3 .

r e a d i n g o f m in u s 3 i n d i c a t e s h i g h l y a c u t e h e a r i n g .

E x p e r im e n ta tio n w it h t h e s e t e s t s

have proved t h a t

e i g h t y p u p i l s p e r h o u r can b e s a t i s f a c t o r i l y t e s t e d e r and an a s s i s t a n t w o r k i n g f o u r h o u r s a d a y . t h r e e hundred t e s t s

a day,

by a t e s t ­

T h is a llo w s

an d f i f t e e n h u n d r e d a s c h o o l w e e k .

T h i s o n e i n s t r u m e n t may b e u s e d i n a s c h o o l s y s t a m a s i t m it s a p p r o x im a te ly f o r t y - f i v e th ou san d t e s t s year.

d u rin g a s c h o o l

A l l p u p i l s who do n o t make a g o o d r e c o r d s h o u l d be

r e t e s t e d , and a t h o r o u g h e x a m i n a t i o n s h o u l d be made b y a n o to lo g is t.

A p r o c e s s known a s s c r e e n i n g i s

Loc. cit.

per­

used in th e

98 sch ool t e s t s

and i n h e a l t h , e x a m i n a t i o n s .

c h ild r e n are d iv id e d in to p a ir e d .

By t h e s e t e s t s ,

two g r o u p s , t h e n o r m a l and t h e

T h ose w ith d e f e c t i v e h e a r in g are s e l e c t e d

tests.

A stu d y of th e

lo g ic a l t e s t s ,

I.

im­

fo r r e ­

i n d i v i d u a l s h o u l d be made b y p s y c h o ­

Qs. , h e a r i n g im p a ir m e n t., h e r e d i t a r y b a c k ­

ground of d e a f n e s s ,

e tc.

Im p ortan t a s t h e s e s c r e e n in g t e s t s s c h o o l s y s te m s w here r a p id group t e s t s

are in t h e la r g e r

are n e c e ss a r y , th e y

do n o t a c c u r a t e l y d e t e r m i n e h e a r i n g im p a i r m e n t on e i t h e r a q u a n tita tiv e

or q u a l i t a t i v e

fo u n d i n t e s t s

b a sis.

An e x a m p le o f t h i s w a s

g i v e n b y D r . H o r a c e N ew h a rt t o t h e E x c e l s i o r

M in n e so ta S c h o o l s i n 1 9 4 1 .

When t h e

test

w i t h t h e M o d e l 4 -C

g r o u p p h o n o g r a p h i c a u d i o m e t e r w i t h f a d i n g num bers w a s g i v e n , o n ly tw e lv e

c h i l d r e n w e r e fo u n d w i t h

Out o f t h e 5 0 0 c h i l d r e n w ith h e a r in g d e f e c t s .

tested ,

a h e a r in g im p a irm e n t.

t h e M a ic o D - 8 d e t e c t e d

S im ila r r e s u l t s

64

have been d u p lic a t e d

i n many h e a r i n g s u r v e y s . T he r e a s o n t h a t t h e tests

fa il

cause i t six , tests

" f a d i n g nu m bers p h o n o g r a p h i c "

t o d e t e c t h e a r in g l o s s i n

tests

o n ly th e d i g i t s :

th e upper t o n e s i s

on e, tw o, t h r e e ,

be­

fo u r, f i v e ,

and eight.*** Many p h y s i c i a n s c o n s i d e r t h a t t h e

o n ly v a l id

u s i n g n u m b ers a r e t h o s e i n w h i c h nu m bers b e g i n n i n g w i t h

***'L. A. W a t s o n , "Why and How t o C on d u ct S c h o o l H e a r ­ in g T e s ts ." P a m p h le t f u r n i s h e d b y t h e c o u r t e s y o f t h e M a ic o C o.

99 "s" a r e u s e d .

A. c h i l d w i t h a h i g h t o n e l o s s may s t i l l

t i n g u i s h t h e n u m b ers b y t h e v o w e l

s o u n d s w h ic h c h a r a c t e r i z e

t h e nu m bers p r e v i o u s l y m e n t i o n e d . nant

sou n d s a t a l l ,

r a tin g .

He may n o t h e a r t h e

and y e t r e c e i v e

The c h i l d n e e d s

and t h i s

th e phonograph t e s t . M ost o f ca ses in

good h e a r in g in t h e h ig h e r c o n so ­

fr e q u e n c ie s.

1 s u r v e y s made h a v e r e p o r t e d m ore

f o r h i g h f r e q u e n c i e s t h a n t h o s e i n th e

S in c e th e l o s s

it

is

c h r o n ic m t h

p r o g r e ssiv e

e v i d e n t t h a t o n e m u s t n o t d e p e n d on t h e s e

f a d i n g n u m b ers a l o n e i n t e s t i n g . " s e le c tiv e "

lo w

fo r h ig h fr e q u e n c ie s d e n o te s a

p e r c e p t i o n d e a f n e s s u s u a l l y w h ic h i s te n d e n c ie s,

in th e vow el range o f

im p a ir m e n t c a n s e l d o m be d e t e c t e d w i t h

th e h e a r in g

th e l o s s

conso­

a " p e r f e c t ” o r " n o r m a l”

n a n t r a n g e e v e n m ore t h a n he n e e d s i t fr e q u e n c ie s,

d is­

At th e

s p e e c h and h e a r i n g t e s t

p r e s e n t t i m e a new

record

t e s t s b o t h v o w e l s and c o n s o n a n t s b y t h e

is

a v a i l a b l e w h ic h

s c r e e n i n g m e t h o d , and

th e c h ild

c h e c k s one o f t h r e e w o r d s w h ic h he t h i n k s w as p r o ­

nounced.

T h ese s e t s o f w ords are arra n g ed a c c o r d in g t o

p itc h

or fr e q u e n c y . When s c h o o l c h i l d r e n h a v e b e e n f o u n d by t h e m e t e r w i t h a h e a r i n g impairment; or d e c ib e l s , th e y

1

4 -A A u d i o ­

b e y o n d 9 o r 10 s e n s a t i o n u n i t s ,

s h e u l d be g i v e n t e s t s w i t h t h e 1 - A ,

Loc. e x t .

2-A ,

3 -A ,

100 5 - A , o r S-A A u d i o m e t e r ,

T h e 1 -A a n d 2 -A A u d i o m e t e r s a r e m o st

g e n e r a l l y found i n c l i n i c s

and o f f i c e s

of o to lo g is ts .

T h ese

h a v e s e l e c t i v e . r a n g e for- a c t u a l h e a r i n g d e f e c t s and a r e d e ­ p e n d e n t on t h e s k i l l o f t h e o p e r a t o r . d iv id u a l t e s t s

T h e s e 1 -A and 2-A i n ­

are l i k e e l e c t r i c

tu n in g f o r k s .

5 -A h a v e a s i n g l e c o m b in e d t o n e ,

in c lu d in g th e

The 3-A and o r d in a r y s p e e c h

r a n g e , a n d a sou n d l i k e t h e " l i n e b u sy " s i g n a l on t h e t e l e ­ phone.

W h i l e t h e 1 -A and 2-A a r e n o t d i f f i c u l t t o

o p era te,

t h e y r e q u i r e m ore t h a n do t h e o t h e r s , t h e s e r v i c e s o f a tr a in e d te c h n ic ia n . T he M a ic o D -5 A u d i o m e t e r , w h i c h w a s u s e d i n t h i s in g iv in g th e t e s t s t o ste n o g r a p h ic s t u d e n t s , s i o n a l a u d io m ete r m t h

stu d y

is a p ro fes--

s p e c ia l d ia g n o stic fe a tu r e s ,

c a lib r a te d

a c c o r d i n g t o t h e r e q u i r e m e n t s o f t h e A m e rica n S t a n d a r d s A s s o ­ c ia tio n

and t h e A m e r ic a n M e d i c a l A s s o c i a t i o n C o u n c i l on P h y ­

s i c a l T herapy.

The M a ic o D -5 A u d io m e t e r i s

t e s t i n g , p u r e -to n e a u d io m e te r , and is a s b e in g

an i n d i v i d u a l -

c la im ed by i t s

sponsors

" th e m o s t w i d e l y u s e d i n s t r u m e n t i n t h e w o r l d f o r

h e a r in g t e s t s . ”

It

g iv e s

b oth a q u a n t it a t iv e a s w e l l a s a

q u a l i t a t i v e m easurem ent o f h e a r in g l o s s .

The in s tr u m e n t h a s

p u r it y o f to n e th rou gh ou t t h e sp eech r a n g e , in 5 p er cen t o f th e p r e sc r ib e d *** G o l d s t e i n , 2

to n e fr e q u e n c ie s has been

op. c i t . , p.

L, A, W a t s o n ,

and a c c u r a c y w i t h ­

op. c i t . ,

143. pp. 1 -4 .

101 a c c o m p lish e d .

The M a ic o Company h a s n u m er o u s o t h e r m ak es o f

a u d i o m e t e r s on t h e m a r k e t a s do m o st o f t h e

o t t e r h e a r in g -a id

and a u d io m ete r c o m p a n ie s. G o ld s te in g iv e s th e m eters:

fo llo w in g

a d v a n ta g es o f a u d io ­

^ (a )

The i n d i v i d u a l t o n e t h r o u g h o u t t h e m u s i c a l s c a l e m ay b e a c c u r a t e l y m e a s u r e d a n d c h a r t e d i n q u a n t i t y and q u a l i t y .

(b )

The t o n e a s p r o d u ce d b y t h e a u d io m e te r i s a p u r e , f u n d a m e n t a l t o n e and f r e e f r o m o v e r t o n e s o r e x tr a n e o u s so u n d s a s d e v e lo p e d by o t h e r in str u m e n ts in f u n c t io n a l t e s t s o f h e a r in g (tu n in g f o r k s e x c e p te d .}

(o )

T he i n t e n s i t y o f t h e t o n e m ay b e d e f i n i t e l y ga u g ed , an a d van tage th u s f a r im p o s s ib le w ith o th er t e s t d e v ic e s .

(d )

B o t h p i t c h and i n t e n s i t y m ay b e s t a n d a r d i z e d and e a s i l y c h a r t e d . The g r a p h s t h u s p r o d u c e d a f f o r d s t a b l e , s c i e n ­ t i f i c d a t a f o r c a r e f u l s t u d y and d i f f e r e n t i a l d ia g n o sis.

R ecen t e x p e r im e n ta tio n h a s r e v e a le d t h a t a u d io m ete rs w i t h h a l f o c t a v e d e t e r m i n a t i o n s a r e m ore i m p o r t a n t f o r s c i ­ e n t i f i c p u r p o s e s th a n a r e th e

sw eep r a n g e o f o c t a v e i n t e r ­

v a l s w h ic h i s t h e u s u a l c a l i b r a t i o n o f a u d io m e t e r s . i s n e c e s s a r y i n a l l bone c o n d u c tio n t e s t s , t i o n w here t h e r e

is

a d iffe r e n c e 0 £.

conduc­

of 40 d e c i b e l s or m ore.

■j

Goldstein,

and i n a i r

M a sk in g

cit., pp. 156-157.

The

102 r e c e n t a u d io m e te r m e a su r e s h e a r in g on th e t e n s i t y , w i t h v a r i a t i o n s o f p i t c h fro m s i x

b a sis of

so u n d i n ­

to e i g h t

an d d e t e r m i n e s h e a r i n g w i t h m a t h e m a t i c a l p r e c i s i o n .

o cta v es, I t has

g r e a t l y r e d u c e d t h e i n c i d e n c e o f im p a ir m e n t i n m o s t s c h o o l s y s te m s w here i t fa cto r

has been u sed .

o f d i s t a n c e w h ic h i s

o f a l l o th er te s ts *

It

e lim in a t e s th e

u n c e r ta in

th e v a r ia b le f a c t o r c h a r a c t e r is t ic

The a u d i o m e t e r t e s t s

a r e m o st r e l i a b l e

i n a s o u n d -p r o o fe d room , and t h e a u d io m e te r sh o u ld be ch e ck ed f o r a ccu ra te now a v a i l a b l e

c a lib r a t io n once a y e a r .

H ig h e r t o n e s th a n a r e

on t h e a u d i o m e t e r m ay b e n e c e s s a r y t o

m a c h i n e i n o r d e r t o s e c u r e a m ore a c c u r a t e t e s t K in n e y

sh o w s t h a t im p ro v em en t

a t 50 and 60 d e c i b e l s h a s a d i f f e r e n t l o s s e s o f 3 0 and 3 0 d e c i b e l s .

add t o t h e

o f h e a r in g .

3-

o f 10 d e c i b e l s w i t h l o s s e s in t e r p r e t a t i o n th an a t

"A 1 0 d e c i b e l im p r o v em e n t a t

\-60 d e c i b e l s ' t o 5 0 d e c i b e l s m ea n s t h a t t h e p a t i e n t

can h ea r

t h e t o n e 9 0 0 , 0 0 0 t i m e s l e s s i n t e n s e l y , w h e r e a s a 10 d e c i b e l im p r o v em e n t fr o m 30 t o

20 m ea n s t h a t h e h e a r s t h a t t o n e o n l y

900 tim e s a s i n t e n s e l y . im p r o v e d 10 d e c i b e l s . " n e c e s s a r y i n b in a u r a l

I n both i n s t a n c e s t h e h e a r in g i s A g r e a t d e a l m ore e x p e r i m e n t a t i o n i s

and s p o k e n v o i c e t e s t i n g ,

and t h e n o r -

m a l h e a r i n g f o r a l l p e o p l e m u st b e more a c c u r a t e l y e s t a b l i s h e d . ^ W a l t e r A. W e l l s , "Some P r a c t i c a l C o n s i d e r a t i o n s w i t h R e g a r d t o H e a r i n g T e s t s . " .A n n a I s o f O t o l o g y , R h i n o l o g y , and L a r y n g o lo g y , 4 9 :4 2 7 , Jun e, 1 9 4 0 . % A l f r e d Lewy and Norman L e s h i n , " F u n c t i o n a l E x a m i n a t i o n o f H e a r in g ." A r c h i v e s o f O t o l o a r y n g o l o g y , 3 5 : 4 5 1 , M arch , 1 9 4 2 .

2

103 D r . Max A . G o l d s t e i n , who w a s f o r y e a r s an a u t h o r i t y on h e a r in g s t a t e d : The a u d i o m e t e r i s d e s t i n e d t o be o n e o f t h e m o st i m p o r t a n t f a c t o r s i n t h e g r e a t p r o b le m o f d e a fn e s s , i t s p r e v e n tio n , th e c l a s s i f i c a t i o n of t y p e s , th e i n v e s t i g a t i o n o f r e m e d ia l m easures a n d a m ore d e f i n i t e k n o w l e d g e o f t h e . p h y s i o l o g y o f h e a r in g . 1 S in c e t h e

a u d io m ete r i s

d e s t i n e d t o b e one at t h e m ost

im p o rta n t in s tr u m e n ts i n d e t e c t i n g h e a r in g im p a ir m e n ts, a c o m m issio n h a s b een o r g a n iz e d s ic is ts ,

and a c o u s t i c e n g i n e e r s ,

o f S ta n d a r d s , w hose d u ty i t m en ts,

c o n sistin g

is

to

of o to lo g is ts,

phy­

i n c o o p e r a t io n w ith th e B ureau crea te

a u d io g r a m s, and p e r fo r m a n c e .

stan d ard s of in s t r u ­

T h is c o m m issio n h a s a c ­

c e p te d th e f o llo w in g in s tr u m e n ts a s b e in g sta n d a r d iz e d a c c o r d ­ i n g t o t h e i r r e q u ir e m e n ts : t h e S on oton e J o n es-K n u d so n , m od el 1 , t h e M a ic o D -5 and t h e ? 7 e s t e r n E l e c t r i c T h is c o m m issio n ,

6-B .

o r b e t t e r known a s t h e

C o u n c i l on

P h y s i c a l T h e r a p y and t h e C o n s u l t a n t s on A u d i o m e t e r s and H e a r ­ in g A id s , h a s r e p o r te d th e

f o l l o w i n g a cco m p lish m en ts i n t h i s

fie ld s 1.

1

Minimum r e q u i r e m e n t s f o r a c c e p t a b l e a u d i o ­ m e t e r s h a v e b e e n f o r m u l a t e d and a d o p t e d . The r e q u ir e m e n ts have r e c e iv e d u n iv e r s a l a c c e p ta n c e on t h e p a r t o f o t o l o g i s t s and m a n u f a c t u r e r s .

G o ld ste in ,

o£.

c i t .,

p. 143.

104 2.

T hree a u d io m e te r s f o r d ia g n o s t ic i n v e s t i g a t e d and a c c e p t e d .

3*

R e q u ir e m e n ts fo r a c c e p t a b le h e a r in g a i d s h ave b e e n f o r m u l a t e d and a d o p t e d .

4.

H e a r i n g a i d s h a v e b e e n i n v e s t i g a t e d and a c ­ c e p t e d o r r e j e c t e d and t h i s i n f o r m a t i o n h a s b e e n a v a i l a b l e t o t h e p r o f e s s i o n and t h e p u b l i c .

5.

A s u r v e y o f m eth od s f a r d e te r m in in g t h e p e r c e n t ­ age of d i s a b i l i t y due t o d e a fn e ss has been s t a r t e d . The H o u se o f D e l e g a t e s a t t h e S t . L o u i s s e s s i o n e n d o r s e d t h e w ork a c c o m p l i s h e d a n d o b j e c t i v e s a im e d a t .

6.

I n f o r m a t io n on d e v i c e s u sed f o r tr e a tm e n t o f h e a r i n g l o s s h a s b e e n made a v a i l a b l e ( e . g . s t i m ­ u l a t i o n o f h e a r in g by s o u n d ).

7.

A d v e r t i s i n g o f a c c e p t a b l e h e a r i n g a i d s and a u d i o m e t e r s h a s b e e n r e v i e w e d , c o n s i d e r e d and c r i t i c i z e d a n d much u n d e s i r a b l e c o p y h a s b e e n e lim in a te d .

8.

The C o u n c i l h a s a s s u r e d h i g h s t a n d a r d s o f c o n ­ s t r u c t i o n , w o r k m a n sh ip and m a t e r i a l . 1

I n o r d e r t o m ake a s c i e n t i f i c a u d io m eter t e s t s ,

use have been

c o m p a r a tiv e a n a l y s i s o f

o r even to d ia g n o se in d iv id u a l c a s e s o f

h e a r i n g im p a ir m e n t , t h e t e s t i n g m ust b e d o n e u n d e r i d e a l c o n ­ d itio n s. te s tin g

The m o s t i d e a l i s is

t h e s o u n d -p r o o fe d room .

When t h e

d o n e u n d e r c o n d i t i o n s w h ic h f a l l s h o r t o f t h e

th e t e s t s are l e s s a c c u r a te , r e lia b le ,

and s c i e n t i f i c ,

id e a l,

and

^ A m e r ic a n M e d i c a l A s s o c i a t i o n , " P r o g r e s s R e p o r t o f t h e C o n s u l t a n t s on A u d i o m e t e r s and H e a r i n g A i d s o f t h e C o u n c i l o n P h y s i c a l T h e r a p y o f t h e A m e r ic a n M e d i c a l A s s o c i a t i o n . " The J o u r n a l o f t h e A m e r ic a n M e d i c a l A s s o c i a t i o n , 1 1 5 : 8 4 5 - 8 5 7 , S ep tem b er, 1 9 4 0 .

*

105 s u b j e c t i v e a l l o w a n c e s m u st be made a c c o r d i n g l y . In t b e f i r s t who i s

p la c e ,

th e te s tin g

c a p a b l e o f m a k in g t h e t e s t s .

s h o u l d b e done b y one

C ru tch ett s u g g e s ts a

c o u r s e o f tw o y e a r s w h i c h a l l p r a c t i c i n g a u d i o m e t r y m u st t a k e . "Some o f t h e g in e e r in g ,

s u b je c ts proposed are p h y s ic s ,

vacuum t u b e a m p l i f i c a t i o n ,

co m m u n ica tio n en ­

a u d io m e tr ic t e s t i n g ,

p s y c h o l o g y , m e c h a n is m o f h e a r i n g , p h o n e t i c s , h i s t o r i c a l

and

c u r r e n t l i t e r a t u r e o n a u d i o m e t e r s and h e a r i n g a i d s . D r . Norman A . W a tso n h a s o u t l i n e d t h e i d e a l c o n d i t i o n s u nder w h ic h a u d io m e te r t e s t s

sh o u ld be g i v e n .

T h ese i d e a l s

a r e en u m erated a s f o l l o w s : 1.

A t e s t room w h ic h i s so q u i e t t h a t t h e p e r s o n t o b e t e s t e d can h e a r no e x t r a n e o u s so u n d u n d e r th e c o n d itio n s o f th e t e s t .

2.

An a u d i o m e t e r w h ic h w i l l p r o v i d e p u r e t o n e s v a r y in g c o n tin u o u s ly i n fr e q u e n c y , o r a t i n t e r ­ v a l s o f , a t m o s t , o c t a v e s o v e r t h e r a n g e 100 t o 8 0 0 0 c y c l e s , and v a r y i n g c o n t i n u o u s l y fr o m 8 0 0 0 t o 2 0 ,0 0 0 c y c l e s - a l l t o n e s w ith i n t e n s i t y s u f f i c i e n t t o t e s t b y b o t h a i r and b o n e c o n d u c ­ t i o n a p e r s o n w i t h a lm o st c o m p le te l o s s o f h e a r in g .

5.

A i r and bone c o n d u c t io n r e c e i v e r s Y/hich d e l i v e r a l l o f t h e sound t o t h e e a r ( o r v i b r a t i o n t o t h e s k u l l ) w i t h no s t r a y sound.

4.

A s u p p l e m e n t a r y m a s k in g d e v i c e , a d e q u a t e f o r m a s k in g o u t t h e b e t t e r e a r w h i l e t h e p o o r e r i s b e in g t e s t e d , y e t not a f f e c t in g th e p oorer e a r .

5.

A m icro p h o n e a d e q u a te f o r c o n v e r s in g w i t h t h e p erso n b e in g t e s t e d .

1

G ordon B e r r y , " H e a r in g and H e a r in g A i d s . " L a r y n g o sc o p e » 5 2 :1 4 8 , February, 1942.

106 A lo n g w it h t h e s e

i d e a l s , D r . W a tso n a l s o f u r n i s h e s o t h e r p e r ­

t i n e n t in fo r m a tio n c o n c e r n in g a u d io m e tr ic t e s t i n g . A lth o u g h a g r e a t d e a l h a s been done to th e v a r ia b le s p o s s ib le

th e p a t ie n t , th e

o f a sin g le

c o n sid e r e d tb a t th e r e

a d a ily v a r ia tio n

is

d iffe r e n c e

in th e

has been

a d u ity o f

a c u i t y i s m ore

in t h e h e a r in g o f th e v a r io u s r a c e s .

in th e r e s u lt s

Of c o u r s e ,

it

and some h a v e c l a i m e d t h a t t h e r e i s a

K in n e y fo u n d t h a t

is

in d iv id u a l,

in a tm o sp h e ric p r e s s u r e , t h a t h e a r in g

a c u t e i n t h e m o rn in g ,

ib e ls

e x a m i n e r , and

A s id e ' f r o m v a r i o u s m e n t a l and n e u r o t i c f a c ­

t o r s w h ic h v a r y t h e t e s t

h e a r in g ,

e lim in a te a l l

i n a u d io m e tr ic t e s t i n g , t h e r e s t i l l

r em a in t h r e e im p o r ta n t o n e s : t h e a u d io m e te r .

1

th ere i s

t h e r e w as a s much v a r i a t i o n a s 10 d e c ­

o f d i f f e r e n t e x a m i n e r s o n t h e sam e p a t i e n t . a lw a y s t h e p e r s o n a l f a c t o r p r e s e n t w h ic h

v e r y im p o r ta n t a s each t e s t

d e p e n d s on t h e

s e s o f t h e i n d i v i d u a l and t h e t e s t i n g r e s u l t s

p erson al respon­ can b e no m ore "i

a c c u r a te th a n th e th ere

is

a lw a y s d i f f e r e n c e s i n t h e d o c t o r ’ s o f f i c e ,

ent o f f ic e s

as w e ll as in th e

d u rin g th e d a y . is

i n d i v i d u a l r e s p o n s e s make t h e m .

same o f f i c e

W h ile t h e t e s t s

are b e in g

T hen, in d i f f e r ­

a t d if f e r e n t tim e s co n d u cted , th e r e

a lw a y s th e p e r s o n a l f a c t o r p r e s e n t w h ic h i s

v e r y im p o r ta n t

Norman A . W a t s o n , ’’I d e a l s and S t a n d a r d s f o r A u d i o ­ m e t e r s and H e a r i n g A i d s . ” A d d r e s s g i v e n t o N a t i o n a l W o r k sh o p , U n iv e r s it y o f S ou th ern C a l i f o r n ia , J u ly 1 2 , 1 9 4 1 . o Lewy and L e s h i n , 0 £ . c i t . , p* 4 5 0 .

107 and v a r i o u s n o i s e s may c a u s e a f l u c t u a t i o n o f 2 0 , d e c ib e ls

d u rin g a s i n g l e

test.

a lm o st im p o s s ib le t o

th e

E v e n w i t h t h e m o st e x p e n ­

s i v e m a t e r i a l s and c a r e f u l p l a n n i n g , i t is

or 40

A s o u n d - p r o o f room i s

* o n l y p l a c e t o a v o i d much e r r o r .

it

50,

effect

h a s b een fou n d t h a t

p e r fe ct a c o u stic a l

con­

d i t i o n s , bu t th e a c c u r a c y of t h e t e s t s w i l l v a r y i n a c c o r d ­ an ce w ith t h e s e c o n d i t i o n s . m eter are th a t i t once,

The s h o r tc o m in g s o f th e

cannot t e s t

la r g e groups of c h ild r e n

and i t c a n n o t a c c u r a t e l y t e s t

th e o to sc o p e i s

a u d io ­

sm a ll c h ild r e n

at

a lth o u g h

b e i n g u s e d f o r th em .

Some o f t h e

e x a m in er s a r e l a z y ,

c a r e l e s s and i n d i f f e r ­

e n t i n m a k in g r e c o r d s , and t h i s e l i m i n a t e s a l l b a s e s o f com­ p a r iso n .

For th e se

r e a s o n s , a l l a u d io m e tr ic t e s t s

made w i t h p a r t i c u l a r a t t e n t i o n d i r e c t e d t o

sh o u ld be

a co m p lete h i s t o r y

and o t o l o g i c e x a m i n a t i o n ,

a r o u tin e t e s t w ith a tu n in g f o r k ,

a u d io m e tr ic t e s t s

and b o n e c o n d u c t i o n a t t h e t h r e s h -

fo r a ir

•.old a s w e l l a s a t t h e h i g h e r l e v e l s o f i n t e n s i t y , iz e d

in te llig ib ility

tio n s as p o s sib le , is

tests

fo r

sta n d a rd ­

under as i d e a l a c o u s t i c a l c o n d i­

na b s o l u t e p r e c i s i o n i n h e a r i n g t e s t s

an u n a tta in a b le id e a l

1 W a lter A. W e l l s ,

in s p ite

op. c i t . ,

of in str u m e n ta l p r e c i s i o n ." ^

p. 457.

CHAPTER V HEARING SURVEYS AND SCHOOL TESTS The a d o p t i o n o f a m eth o d f o r h e a r in g in J a n e , w as t h e r e s u l t

e stim a tin g th e lo s s

of

1 9 4 2 ^ b y t h e A m e r ic a n M e d i c a l A s s o c i a t i o n

o f many y e a r s o f r e s e a r c h a n d e x p e r i m e n t a ­

t i o n w h i c h w a s b e g u n w i t h t h e i n v e n t i o n o f t h e t e l e p h o n e and th e e sta b lish m e n t

o f th e B e l l S y stem .

on h e a r i n g h a s b e e n due t o t h e

Much o f t h e r e s e a r c h

e n t h u s i a s m and p r o g r e s s i v e

e f f o r t s i n t h e B e l l T e l e p h o n e L a b o r a t o r i e s and many c o n t r i b ­ u tin g a g e n c ie s as a c o u s tic a l

e n g in e e r s,

o to lo g is ts,

and

s p e c i a l w o r k e r s i n m a k in g n a t i o n - w i d e h e a r i n g s u r v e y s and in

c o n d u c t in g num erous t e s t s

in c lin ic s

i n t h e p u b lic s c h o o l s th ro u g h o u t t h e I t was f i r s t

n ecessary

to

a n d m o st r e c e n t l y

n a tio n .

a n a l y z e s o u n d and t o

e n t i a t e b e t w e e n s o u n d s w h i c h se e m e d v e r y n e a r l y a l i k e t h e y a r e p e r c e i v e d b y t h e m in d . ly ,

it

d iffe r ­ as

To s t u d y t h e p r o b le m t h o r o u g h ­

w as n e c e s s a r y t o r e p r o d u c e t h e h e a r i n g m e c h a n is m by

m ea n s o f m e c h a n i c a l d e v i c e s t o

su ch a h ig h d e g r ee of e f f i ­

c i e n c y t h a t no i m p e r f e c t i o n s c o u l d b e d e t e c t e d by t h e m o st p erfect

ear.

As h e a r i n g t e s t d e v i c e s d e p e n d on h e a r i n g f o r

th e ir p e r fe c tio n ,

and a s a h i g h p e r c e n t a g e o f e a r s h a v e some

t y p e o f h e a r i n g i m p a i r m e n t , t h e p r o b le m h a s dem anded t h e a t ­ te n tio n

o f t h e m ost e x a c t s c i e n t i s t s

c a l e n g i n e e r i n g w h ic h s c i e n c e

i n o t o l o g y and a c o u s t i ­

c o u ld p r o d u ce .

109 H.

D. A r n o l d , D i r e c t o r o f R e s e a r c h , B e l l T e l e p h o n e

L a b o r a to r ie s , w rote: Our e a r s a r e o n l y m a c h i n e s t o t r a n s l a t e a i r w a v e s i n t o a form s u i t e d t o s t i m u l a t e t h e a u d i t o r y n e r v e ; a n d a s m a c h i n e s we may m e a s u r e and d e s c r i b e t h e m i n t h e sam e t e r m s t h a t a p p l y t o d e v i c e s we o u r s e l v e s c o n s t r u c t . We may com p are th e m a s t o p e r f o r m a n c e , and may accom m od ate o u r d e v i c e s t o t h e i r r e q u i r e m e n t s . B u t , t o u n d e r s t a n d t h e m e c h a n is m o f t h e e a r i s b y no m e a n s t o u n d e r s t a n d t h e a c t o f h e a r ­ in g , f o r we have n o t heard u n t i l t h e b r a in h as p e r c e iv e d th e m essage se n t by th e a u d ito r y nerve. W ith a s t u d y o f p i t c h , l o u d n e s s , e le m e n t s - o f sou nd a s f r e q u e n c y , d ea fn ess, to

and s p e e c h

n o ise ,

in te n sity ,

in te r p r e ta tio n ,

it

and o t h e r

b in a u r a l h e a r in g ,

has been p o s s ib le

c o n s t r u c t m e c h a n i c a l d e v i c e s w h ic h can t e s t h e a r i n g w i t h

a h ig h degree of a c cu ra c y ,

and b y a q u a n t i t a t i v e m ean s o f

m e a su r in g th o u sa n d s o f e a r s under a l l t y p e s o f c o n d i t i o n s in w h ic h h e a r in g f u n c t i o n s ,

and b y a q u a l i t a t i v e m ea n s o f exam­

i n i n g t h e h e a r i n g m e c h a n is m i n i t s

e n tir e ty ,

e s ta b lis h a sta n ­

dard o f a v e r a g e h e a r in g . It

i s w e l l known t h a t i m p a i r e d h e a r i n g v a r i e s i n p r e ­

v a le n c e and

k in d a s w e l l a s

h e a r in g can b e m ade, i t

is

in d egree.

B efore su rv ey s in

n e c e s s a r y t o make p l a n s f o r e o n -

1 H a r v e y F l e t c h e r , S p e e c h an d H e a r i n g . D. Van H o s t r a n d Company, 1 9 2 9 ) , p p . x i - x i i .

(Hew Y o r k :

110 tr o llin g th ese

v a r ia b le

are:

age, se x ,

n e s s , p sy c h ic lis h e d

Some o f

em p lo y m en t s t a t u s , f a m i l y i n c o m e , s i c k ­

c o n d i t i o n , an d p e r s o n a l i t y .

as a r e s u lt of th ese

c o r d in g t o ic

f a c t o r s i n a s y s t e m a t ic m anner.

I t has been e s ta b ­

su rv ey s th a t h e a r in g v a r ie s a c ­

s e x and c h r o n o l o g i c a l a g e ,

and t h a t i t

is

a chron­

i m p a ir m e n t w h i c h i n f r e q u e n t l y r e m a i n s c o n s t a n t and u s u a l l y

g e t s w orse. H e a r i n g im p a ir m e n t d is a b ility as it sense

is

i s a s e r i o u s o c c u p a t i o n and s o c i a l

”a f u n c t i o n a l d e g e n e r a t i o n o f an i m p o r t a n t

o r g a n r e s u l t i n g fr o m a t t a c k b y b o t h c h r o n i c d i s e a s e s

and a c u t e i l l n e s s e s

.

.

. G eneral s y s t e m ic d e b i l i t y

a t e d w i t h n u t r i t i o n a l d e f i c i e n c y and t o x i c

a sso c i­

s t a t e s lik e w is e

c o n t r i b u t e t o n o r m a l f u n c t i o n i n g c£ t h e a u d i t o r y n e r v e and m u s c l e s y s t e m and c o n s e q u e n t l y i n f l u e n c e t h e a b i l i t y

to h e a r .

H e a lth i s

la tte r

is

r e l a t e d t o th e

s ta n d a r d o f l i v i n g , and t h e

r e l a t e d t o f a m ily in c o m e .” 1 THE UNITED STATES FUBLIC HEALTH SERVICE SURVEY One o f t h e f i r s t

W i l i i s C. B e a s l e y ,

im p o r ta n t

s u r v e y s was c o n d u c te d by

N a tio n a l I n s t i t u t e

of H e a lth , B e th e sd a ,

M a r y l a n d , i n 1 9 3 5 and 1 9 3 6 , u n d e r t h e a u s p i c e s o f t h e U n i t e d

^ W i l l i s C. B e a s l e y , " C h a r a c t e r i s t i c s and D i s t r i b u t i o n o f I m p a ir e d H e a r i n g i n t h e . P o p u l a t i o n o f t h e U n i t e d S t a t e s . ” J o u r n a l o f t h e A c o u s t i c a l S o c i e t y o f A m e rica , 1 2 : 1 1 4 - 1 2 1 , J u ly , 1941.

Ill S t a t e s P u b lic H e a lth S e r v ic e .

It~~was a n a t i o n w i d e i n v e s t i ­

g a t io n co n d u cted by th o r o u g h ly t r a in e d sta n d a rd s e r i e s of q u e s t io n s . h i s t o r y w as m a d e . la tio n

A c lin ic a l

The g r o s s s i z e

s a m p le w a s e q u i v a l e n t t o

h i s t o r y and a s o c i a l

o f t h e H e a lth Survey popu­

3 .7

p er c e n t of th e

ban p o p u la tio n o f th e U n ite d S t a t e s . c u r e d i n f o r m a t i o n on t h e

en u m erators h a v in g a

1950 ur­

T h ese en u m erators s e ­

c o n d i t i o n o f h e a r i n g f o r e a c h member

o f t h e h o u s e h o l d t h r o u g h i n t e r v i e w s b y m ea n s o f h o u s e - t o - h o u s e c a n v a ss in g of p e o p le r e p r e s e n t a t iv e b u tio n o f th e p o p u la tio n . o f h e a r i n g im p a ir m e n t

of a n a tio n -w id e d i s t r i ­

The e n u m e r a to r s c l a s s i f i e d

under the

th e ty p e

f o llo w in g groups:

1.

P a r tia l d ea fn ess, c lo s e range.

sta g e 1.

Can h e a r a t

3.

P a r tia l d e a fn e ss, sta g e 3. T h o s e who h a d d i f f i c u l t y o f h e a r in g d ir e c t c o n v e r s a tio n a t.c lo s e range.

5.

P a r tia l d e a fn e ss, sta g e 3. Can h e a r a m p l i ­ f i e d sp eech w i t h h e a r in g a i d s .

4.

T o ta l d ea fn ess for sp eech . Cannot h ea r sp eech under any c ir c u m sta n c e s .

5.

Mute d e a f . The i n d i v i d u a l w as b o r n d e a f or a c q u ir e d s e v e r e d e a f n e s s so t h a t he can­ not l e a r n sp eech by t h e u s u a l m eans. 1

T h i s i n t e r v i e w t y p e o f i n v e s t i g a t i o n w as r e c o r d e d a s " H ea r in g L o s s e s A c c o r d in g t o S o c i a l H is t o r y

1 Ibid. p. 114.

o f I m p a ir e d H e a r -

112 in g .* 1

T he s i g n i f i c a n c e

so n s w ere n o t r e p o r t e d ,

o f t h i s r e p o r t w as a s f o l l o w s : on t h e

average,

P er­

as h a v in g s ta g e 1

d e a f n e s s or w o r se u n l e s s t h e y had a t t a i n e d h e a r in g l o s s e s t o t h e e x t e n t o f 4 6 and. 4 8 d e c i b e l s on t h e r e sp e c tiv e ly .

S ta g e 2 d e a fn e ss - i s

S tage 3 d e a fn e ss - i s sp eech i s

at

a t 89 d e c i b e l s .

1 0 2 4 and 2 0 4 8 c y c l e s ,

at a le v e l

o f 55 d e c i b e l s .

68 d e c i b e l s , and t o t a l d e a f n e s s f o r Due t o

th e c h a r a c te r o f t h e s e l o s s e s ,

i t w a s i n f e r r e d t h a t h e a r i n g i m p a i r m e n t s among t h e s e p e o p l e h a v i n g a n 89 d e c i b e l l o s s i s t h a t The c l i n i c a l

of n erve d e a fn e s s .

f in d in g s o f th e 9 ,5 2 4 p e r so n s s tu d ie d

w h i c h w e r e a s a m p le o f t h o s e

i n t e r v i e w e d i s more i m p o r t a n t .

Two c o m p l e t e s e t s o f a u d i o g r a m s w e r e o b t a i n e d f o r b o t h e a r s by a ir

c o n d u c t i o n and b o n e c o n d u c t i o n f o r

d e s c end i n g ~ a p p r o a c h to- t h e t h r e s h o l d . d e f i n e d a s b e i n g o f . "no n o t i c e a b l e n ess in

th e c l i n i c a l

h e a r in g l o s s

co m p a re d w i t h 47 d e c i b e l s f o r

N orm al h e a r i n g w a s h e r e

d iffic u lty . n

in v e stig a tio n is

o f 2 4 d e c i b e l s on t h e

th e a sc e n d in g and

S ta g e 1 d e a f­

e q u iv a le n t

t o an a v era g e

1 0 2 4 and 2 0 4 8 c y c l e s ,

s o c ia l h isto r y ,

sta g e 1.

as T hus,

a c c o r d in g t o s o c i a l h i s t o r y , p e r s o n s w ere n o t r e p o r t e d u n l e s s t h e y had a t t a i n e d h e a r in g l o s s e s t o t h e e x t e n t d e c i b e l s o n t h e 1 0 2 4 and 2 0 4 8 c y c l e s .

o f 46 and 48

T h is su r v e y r e v e a le d

t h a t o n e o u t o f e v e r y 7 8 m a l e s and on e o u t o f 8 5 f e m a l e s h ad a n im p a ir m e n t o f h e a r i n g t o t h e e x t e n t

o f 47 d e c i b e l s o r w o r s e .

115 Among c h i l d r e n o f grammar s c h o o l a g e , o f 539 m a l e s ,

5 t o 14 y e a r s ,

one o a t

and on e o a t o f 4 4 2 f e m a l e s h a v e s t a g e 1 d e a f n e s s

or w o rse. ^ "Among p e r s o n s o f s c h o o l a g e and y o o n g a d a l t s y e a r s ) , one o a t

of e v e r y 273 m a le s,

( a n d er 25

a n d o n e o a t o f 34 9 f e m a l e s

i n t h e l o w e s t in c o m e g r o a p h a v e s t a g e 1 d e a f n e s s o r w o r s e , w h e r e a s i n t h e h i g h e r in c o m e g r o u p s ,

o n ly one oat of ev er y

4 0 4 m a l e s , and o n e o a t o f 6 1 3 f e m a l e s a r e im p a r e d t o e x te n t."

th is

2

T h is ,

as w e ll as o th er su rv ey s,

th e f a c t th a t h e a r in g l o s s

is

f o u n d more com m only among t h e

l o w e r in c o m e g r o u p s t h a n among t h e a l d e fic ie n c y is

one of t h e

ten d s to e s t a b lis h

h i g h e r , and t h a t n u t r i t i o n ­

c o n t r ib u t in g f a c t o r s to the

v a l e n c e o f h e a r in g im p a ir m e n t.

pre­

H er e i t w a s f o u n d t h a t t h e

r a t e s a r e f r o m 25 t o 1 1 2 p e r c e n t h i g h e r f o r t h o s e i n t h e l o w e r in c o m e g r o u p group

( $ 1 0 0 0 and u n d e r ) t h a n t h o s e i n t h e h i g h e r

( $ 3 0 0 0 and o v e r ) .

3

THE HEW YORK AHD SAN ERANCISC0 WORLD'S HAIRS' HEARING TESTS U nder th e

d ir e c t io n of J .

C. S t e i n b e r g and h i s a s s o ­

c i a t e s o f t h e B e l l T e le p h o n e L a b o r a t o r i e s , t h e B e l l S y stem

1 Ib id ,

PP* 1 1 4 - 1 2 1 .

2 ib id , p. 114.

3 Ibid, p. 121.

114 c o n d a c t e d a n a t i o n - w i d e s u r v e y i n 1 9 3 9 w h ic h made a v a i l a b l e th e h e a r in g r e c o r d s o f p le .

T h is i s

th e

some t h r e e - q u a r t e r s o f a m i l l i o n p e o ­

la r g e s t h e a r in g t e s t

U n ite d S t a t e s P u b lic H e a lth S e r v ic e 9000 p e o p le .

e v e r c o n d u cte d a s th e

su r v e y in c lu d e d about

The p u r p o s e o f t h e t e s t s a t t h e W o r ld ’ s F a i r s

w as to le a r n th e h e a r in g c h a r a c t e r i s t i c s o f th e p o p u la t io n so th a t

i t w o u ld b e p o s s i b l e

i t m ore e f f i c i e n t

t o im p r o v e t h e s y s t e m and make

i n m e e tin g th e

r e q u ir e m e n ts of t h e p e o p le .

V a r i o u s c o r r e l a t i o n s r e g a r d i n g a g e , s e x , a n d c o l o r w ere made w i t h th e t e s t s . The t e s t i n g w a s c o n d u c t e d i n s e v e n w h ic h w ere p a r t i a l l y one person*

screen ed .

The t e s t s

s o u n d - p r o o f e d room s

E a ch o f th e m ac co m m o d a te d o n l y

and i n s t r u c t i o n s w ere g iv e n th ro u g h

t e l e p h o n e r e c e i v e r s w h ic h t h e t h e im p r e s s io n s on a c a r d .

v isito r

h e l d t o h i s e a r m a r k in g

One t y p e o f t e s t

m e a n s o f s p o k e n w o r d s o f two n u m b e r s .

w as g i v e n b y

E ach p a i r w a s g i v e n a t

a s u c c e s s i v e l y l o w e r v o lu m e u n t i l t h e t w e l v e p a i r s h a d b e e n p r o n o u n c e d ,/ .

T hen t h e t e s t was r e p e a t e d w i t h a d i f f e r e n t

se r ie s. A n o t h e r .t y p e o f t e s t w h i c h w a s g i v e n w a s o n e i n w h ic h t h e tw o n u m b ers w e r e r e p l a c e d b y p u r e m u s i c a l t o n e s , t o n e b e i n g sou n d ed from one to t h r e e t i m e s , and t h e w r o t e down th e tests,

number o f t i m e s t h e

each c o n s i s t i n g o f n in e

so u n d w a s h e a r d .

each lis te n e r s " F iv e

s e ts o f to n es at su c c e s siv e ly

115 lo w e r v o lu m e s , w ere g i v e n .

The f i r s t w a s a t a m o d e r a t e l y l o w

p itc h ,

4 4 0 c y c l e s p e r s e c o n d , TAhich c o r r e s p o n d e d t o

m id d le

M0 W o n t h e p i a n o .

"A" a b o v e

Each f o l l o w i n g t e s t w as an o c t a v e

h i g h e r i n p i t c h , and t h u s t h e h e a r i n g w a s t e s t e d a t 4 4 0 , 8 8 0 , 1 7 6 0 , 3 5 2 0 , and 7040 c y c l e s . to n es,

e ith e r 1,

er th a n th e fo r th e

2,

For each p i t c h , n in e s e t s o f

o r 3 w ere so u n d e d .

one p r e c e d in g i t .

l i s t e n e r to h ea r,

b e r o f th o s e g iv en th e

When t h e

E ach sou nd w a s f a i n t ­ sou nd s w ere t o o f a i n t

he c o u l d o n l y r e c o r d f r o m t h e

num­

s o u n d s w h i c h he h e a r d , and i n t h a t

m a n n er a m e a s u r e m e n t o f h i s h e a r i n g a c u i t y w a s o b t a i n e d . B efo re

e a c h t e s t w a s g i v e n , t h e a t t e n d a n t c h e c ic e d t h e

c a r d a s t o w h e t h e r t h e t e s t e e w a s m a l e or f e m a l e ,

c o lo r e d

o r w h i t e , and h i s a p p r o x i m a t e a g e b y p l a c i n g h im i n o n e o f th e f iv e

age grou p s:

1 0 -1 9 , 2 0 -2 9 , 4 0 -4 9 , or 5 0 -5 9 .

r e c o r d w a s p h o t o g r a p h e d on a f i l m and t r a n s f e r r e d t o " p u n ch c a r d ” a t t h e L a b o r a t o r i e s , su lts,

age, se x ,

The a

i n d i c a t i n g t h e h e a r in g r e ­

c o lo r of th e s u b j e c t ,

and t h e d a t e and h o u r

t h e t e s t was m ade. -in g m a c h in e s,

T he c a r d s w e r e t h e n s e n t t h r o u g h t a b u l a t 1 a n a l y z e d , and summed”

T he r e s u l t lo w s:

o f th e

a n a ly se s of th e s e

records is

as f o l ­

"B oth men and women sh ow ed i n c r e a s i n g h e a r i n g i m p a i r ­

1 J . C. S t e i n b e r g , and H. 0 . M o n tg o m e r y , " A n a l y s i s o f t h e W o r l d ’ s F a i r s ’ H e a r i n g T e s t , ” P a m p h le t r e p r i n t e d f r o m B e l l L a b o r a t o r i e s Re c o s'd , c H e c e m b e r , 1 9 3 9 .

116 m ent w ith i n c r e a s i n g a g e . p e c ia lly

3520 c y c l e s , t h e

For t h e h ig h f r e q u e n c y t o n e s , effect

i s m ore p r o n o u n c e d i n man

t h a n i n women, b u t f o r l o w t o n e s t h e t o a sm a lle r d e g r ee .

At 1 7 6 0 c y c l e s ,

f e r e n c e b etw een th e h e a r in g lo w er f r e q u e n c ie s , group

(1 0 t o

o p p o site th ere i s

i s t r u e , th ou gh a little

o f men and t h a t o f wom en.

d if­ At t h e

t h e h e a r i n g o f m em bers o f t h e l o w e s t a g e

19 y e a r s )

b e r s o f th e n ext

es­

is

s l i g h t l y poorer th an th a t

o ld e r group.

o f mem­

T h i s i s p r o b a b l y due t o t h e

g r e a t e r d i f f i c u l t y o f th e y o u n g er c h ild r e n i n u n d e r sta n d in g th e t e s t

and w r i t i n g t h e i r r e s p o n s e s on t h e

test

b la n k .”

A h e a r in g l o s s o f 25 d e c i b e l s a t f r e q u e n c i e s up t o 1 7 6 0 c y c l e s , w h ic h i s a b e g i n n i n g h a n d i c a p w as foun d i n abou t 1 . 5 p e r c e n t o f t h e you n g p e o p l e , o r 3 o u t o f 2 0 0 , a n d i n almost^ t e n t i m e s a s many o f t h e o l d e s t a g e r a n g e , 5 0 - 5 9 , o r e v e r y sev en th p erson. H ig h t o n e d e a f n e s s , a l t h o u g h n o t s o im ­ p o r ta n t f o r t h e u n d e r s ta n d in g o f s p e e c h , i s i n d i c ­ a t i v e o f a p r o g r e s s i v e c o n d i t i o n w h i c h may l a t e r in v o lv e t o n e s o f lo w er fr e q u e n c y . Some 6 p e r c e n t o f t h e p e r s o n s i n t h e 20 t o 29 a g e g r o u p sh ow ed a l o s s o f m ore t h a n 20 d e c i b e l s f o r t h e 7 0 4 0 c y c l e , w h e r e a s a l m o s t 50 p e r c e n t i n t h e o l d e s t a g e g r o u p , 50 t o 59 sh ow ed i t . . . A c o m p a riso n o f t h e t e s t s made a t b o t h f a i r s sh o w e d no a p p r e c i a b l e d i f f e r e n c e s a t t h e t h r e e lo w e r f r e q u e n c i e s and v e r y l i t t l e i n g t h e woman a t t h e t w o h i g h e r f r e q u e n c i e s .

L oc. c it * 2

A l f r e d Lew y, a n d Norman L e s h i h , " F u n c t i o n a l Exam­ i n a t io n o f H e a r in g .” A r c h iv e s o f O to la r y n g o lo g y , 3 5 :4 3 7 -4 4 7 , M a r c h , 1942,.

117

T here i s

a w id e v a r i a t i o n c o n c e r n i n g t h e am ount o f

d e a f n e s s and i m p a i r e d h e a r i n g t h a t h a s b e e n f o u n d among sch ool c h ild r e n .

One r e p o r t s t a t e s

and t h e U n it e d S t a t e s

th a t

i n G erm any, R u s s i a ,

t h a t more t h a n 2 0 p e r c e n t o f t h e s c h o o l i

c h i l d r e n h a v e b e e n fo u n d to h ave d e f e c t i v e h e a r in g . berg,

it

was r e p o r t e d t h a t f i f t y - t h r e e

h e a r in g .1

p e r c e n t had d e f e c t i v e

A n o th er s tu d y fo u n d t h a t one i n 17 c h i l d r e n ,

s i x per cen t o f over a m illio n h e a r in g .

I n H ans-

It

is

s c h o o l c h i l d r e n had im p a ir e d

c o n sid e r e d th a t te n

t i o n w o u ld h a v e d e f e c t i v e h e a r i n g i f s o u n d - p r o o f e d ro om .

T h is h ig h

or

p er c e n t o f th e p o p u la ­ t h e y w ere t e s t e d

in c id e n c e

in a

o f h e a r in g l o s s

is

d o u b t l e s s a f f e c t i n g h u n d r e d s o f t h o u s a n d s o f c h i l d r e n , and m a k in g e d u c a t i o n a d i f f i c u l t p r o c e s s f o r th e m .

The U n i t e d

B ureau o f E d u c a tio n e s t im a t e s t h a t t h e r e a r e 5 0 0 ,0 0 0 c h i l ­ d r e n i n t h e c o u n t r y who n e e d s p e c i a l e d u c a t i o n on a c c o u n t p o f d e f e c t iv e h e a r in g . F o r many y e a r s t h e h e r e d i t y f a c t o r w as c o n s i d e r e d a s one o f th e m ost im p o r ta n t c a u s e s o f im p a ir e d h e a r in g x

-

Edward H. C a m p b e ll and L o u i s E . S i l c o x , " P r o g r e s s i v e D e a f n e s s . ” L a r y n g o s c o p e , 5 2 : 4 0 5 , M ay, 1 9 4 2 . 2 W a l t e r A . W e l l s , "Some P r a c t i c a l C o n s i d e r a t i o n s w ith R egard t o H e a r in g T e s t s . ” A n n a ls o f O t o lo g y , R h in o l o g y , and L a r y n g o lo g y . 4 9 : 3 6 8 - 3 6 9 , J u n e , 1 9 4 0 .

118 and d e a f n e s s * .

Of 3 1 3 f a m i l i e s o f s e r i o u s

d ea fn ess,

p e r c e n t r e v e a le d t r u e h e r e d i t a r y d e a fn e ss'; t r u e ity

o n ly 5

c o n sa n g u in ­

o c c u r r e d o n l y t h r e e t i m e s and i n t h e s e i n s t a n c e s t h e

f a t h e r and m o t h e r w e r e f i r s t

c o u sin s.

The o t h e r c a s e s r e p r e ­

se n te d b io lo g ic d e f e c t s m a n ife ste d e i t h e r a t or d i r e c t l y a f t e r b i r t h due t o and o t i t i c w h ile

s p in a l m e n in g itis ,

in fe c tio n s.

upper r e s p i r a t o r y ,

I n 13 in s t a n c e s t h e f a t h e r was d e a f ,

i n 1 1 o n l y t h e m o t h e r had d e f e c t i v e

about th ree per cent a lr e a d y in

of th e

h e a r in g .

c h ild r e n a r e d e a f,

1

O n ly

and t h e y a r e

sc h o o ls fo r th e d e a f.

O t h e r f a c t o r s w h ic h c a u s e c h r o n i c p r o g r e s s i v e d e a f ­ n e s s a r e g i v e n b y G ran t S e l f r i d g e a s f o l l o w s : th a t

e str o g e n ic

He f o u n d

s u b s t a n c e s p l a y an i m p o r t a n t r o l e

c o n d u c tio n d e a fn e s s ; t h a t t h y r o id , p i t u it a r y c o r t e x a r e im p o r ta n t i n t h e tr e a tm e n t; t h a t o t i n i c a c id are h e lp f u l w ith

and a d r e n a l t h i a m i n and n i c ­

c o m p le x and o t h e r v i t a m i n s ;

t h a t n e it h e r bone nor a i r c o n d u c tio n d e a fn e s s i s sin g le

in th e

cau sed by

f a c t o r s b u t v a r io u s o n es r e l a t e d t o g ro w th , endo­

c r in e g la n d s,

v ita m in s , m in e r a l s a l t s

and am in o a c i d s ;

(th e

e le c tr o ly te s)

t h a t d i e t a r y e r r o r s and e n c o d r i n e d i s t u r b -

^ W a l t e r H u g h so n and E . G. W i t t i n g , " E s t i m a t i o n o f Im p rovem en t i n H e a r i n g F o l l o w i n g T h e r a p y o f D e a f n e s s . " A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 4 9 : 3 6 8 - 3 6 9 . June, 1940.

119 a n c e s d a r in g g e s t a t i o n T h erefore, ness is

cause d e a fn e s s . ^

th e e a r l i e r

th at

c h r o n ic p r o g r e s s iv e d e a f­

d e t e c t e d , t h e m ore c h a n c e s t h e r e a r e t o c u r e

to trea t p r a ise d

it.

E a c h c a s e m u st b e s t u d i e d

in th e lig h t

n a tu re o f i t ,

imp a i r inert , t h e

and i t s p r o g r e s s i v e t e n d e n c i e s .

r e su lta n t d is a b ilit y ,

or

s e p a r a t e l y and a p ­

of t h e h i s t o r y o f th e

t r ib u t in g f a c t o r s in c lu d e d in

it,

O th er con ­

such a stu d y sh o u ld b e t h e

o c c u p a tio n a l s t a t u s , a s w e l l a s th e

i n d i v i d u a l p s y c h o lo g ic r e a c t i o n r e g a r d in g h i s im p a irm e n t. K e r r id g e fo u n d t h a t

"The m a j o r i t y o f d e f e c t s o f h e a r i n g i n

c h i l d r e n a r e due t o

c h r o n ic m id d le ear d i s e a s e — e i t h e r s u p ­

p u r a tiv e or c a ta r r h a l. p a ir m en t due t o in g i n th e

c o ld s,

H e a r in g i s

very su sc e p tib le to

in fe c tio u s d ise a se s,

to x in e s o r ig in a t­

b o d y and c h e m i c a l a g e n t s f r o m w i t h o u t a s w e l l a s

from e x c e s s i v e n o i s e s e x p e r ie n c e d i n t r a f f i c tio n ,

im ­

and t r a n s p o r t a ­

commerce and c o n s t r u c t i o n a s we 1 1 a s i n m a c h i n e s h o p s

o f v a r io u s k in d s . a d e c lin e

It

h a s b e e n fo u n d t h a t t h e r e

is g e n e r a lly

i n h e a r in g a c u i t y a f t e r t h e age o f f i f t y ,

and t h a t

th e g r a d e s o f im p a ire d h e a r in g a r e ab ou t e q u a l l y d i s t r i b u t e d in b oth s e x e s a f t e r t h i s age h a s b een r e a c h e d . set,

d e g ree of h e a r ir g 1

lo ss,

The a g e o f on­

and d u r a t i o n v a r i e s w i t h i n d i -

G ran t S e l f r i d g e , " C h r o n ic P r o g r e s s i v e D e a f n e s s w i t h S p e c i a l R e f e r e n c e t o E s t r o g e n i c S u b s t a n c e s ," A n n a ls o f O t o lo g y , R h in o l o g y , a n d L a r y n g o l o g y , 4 9 : 7 3 , M a r c h , 19,40.

ISO v id u a ls .

The p s y c h o l o g i c a l a f f e c t s o f t h e d i s e a s e

in d iv id u a l depends on a g e , h e a lt h , s o c ia l a ttitu d e ,

d is p o s itio n to

n a tu re o f w ork, r e s o u r c e f u ln e s s ,

e n v iro n m en t,

d iffic u ltie s ,

e x p e r ie n c e ,

in te llig e n c e ,

and s e n s e o f h u m o r.

c a s e s o f im p a ire d h e a r in g , t h e f a c t o r in d iv id u a l is

on t h e

In

of a d a p ta tio n of th e

of p a r tic u la r s ig n if ic a n c e .

1

The s u r v e y s and t e s t s w h ic h h a v e b e e n c o n d u c t e d on s c h o o l c h i l d r e n p r e s e n t t h e m o st t h o r o u g h and t h e m o st r e ­ cent

research in t h is

fie ld .

Some o f t h e m o s t s i g n i f i c a n t

c o n tr ib u tio n s are p r e sen ted . THE JOHNS HOPKINS HOSPITAL STUDY F or s i x t e e n y e a r s t h e O t o lo g i c a l L a b o ra to ry o f th e J o h n s H o p k in s H o s p i t a l h a s s t u d i e d t h e p a t h o lo g y and m eth o d s o f trea tm en t

of th e p r e v e n tio n of d e a fn e s s .

F ou rteen y e a r s

o f t h a t t i m e w a s d e v o t e d t o t h e c l i n i c a l e x a m i n a t i o n s and f u n c t io n a l t e s t s w ith a h i s t o l o g i c

stu d y of th e h e a r in g

m e c h a n is m a f t e r d e a t h , a n d c o r r e l a t i o n s m a d e . done w it h t h e and v o i c e As t h i s

T e s t i n g was

1 -A W e s t e r n E l e c t r i c A u d i o m e t e r , t u n i n g f o r k s ,

on some 1 5 , 0 0 0 p a t i e n t s ,

3 0 0 0 o f whom w e r e c h i l d r e n .

and o t h e r s t u d i e s h a v e p o i n t e d

out th a t

a p p r o x im a te ly

a l l t y p e s of~ i m p a i r m e n t s o f a d u l t s a r e a l s o f o u n d i n

1

Ib ia.

r 5 3 :381

c h ild r e n ,

it

has been c o n sid e r e d t h a t th e

s t a d y o f c h i l d r e n ’ s com m uni-

c a b l e d i s e a s e s and h e a r i n g i m p a i r m e n t s w o u ld a l s o p r o b le m s o f

s o lv e th e

d e f e c t i v e h e a r in g fou n d i n a d u l t s .

Of t h e

3000 c h ild r e n

stu d ie d ,

1 3 6 5 who h a d d e f e c t s

in h e a r in g w ere g iv e n fu r th e r

e x a m i n a t i o n and s t u d y .

c h i l d r e n w e r e fr o m t h e . p u b l i c

and p a r o c h i a l s c h o o l s o f B a l ­

tim o r e ,

and w e r e f r o m 8 t o 1 4 y e a r s o f a g e .

t h e s e a r e t o b e e x a m in e d f o r t h e

T hese

About 700 o f

n e x t 5 o r 10 y e a r s i n o r d e r

t o s t u d y m ore c o n c e r n i n g t h e p r o g r e s s i v e t e n d e n c i e s o f t h e v a r io u s im p a irm e n ts.

A l l but a sm a ll p e r ce n ta g e of th e s e

3 0 0 0 c h i l d r e n e x a m in e d w e r e c o n s i d e r e d b y t h e i r t e a c h e r s t o have good h e a r in g .

The f i n d i n g s a re a s f o l l o w s :

^

1)

t h a t o n ly 5 8 .8 p er cen t o f t h e s e 1365 c h ild r e n have norm al h e a r in g f o r a l l t o n e s f r o m 32 t o 1 6 , 3 8 4 d . v . A ll t e s t s w e r e made i n s o u n d - p r o o f r o o m s .

2)

t h a t 3 6 .3 p e r c e n t o f t h e s e 1365 c h ild r e n have im p a ir e d h e a r in g f o r h ig h t o n e s w it h n o r m a l h e a r i n g f o r l o w t o n e s and t h e v o i c e . I t i s a d e f i n i t e but a c u r io u s f a c t th a t t h i s t y p e o f i m p a i r e d h e a r i n g i s much m ore common in b o y s th an i n g i r l s . O n ly 30 p e r c e n t o f t h e g i r l s w e r e a f f e c t e d , ■b u t 5 2 . 7 p e r c e n t o f t h e t o y s had im p a ir e d h e a r in g f o r h ig h t o n e s w i t h norm al h e a r in g f o r lo w t o n e s and f o r t h e v o ic e .

3)

t h a t o n l y 5 p e r cen b o f t h e s e 1 3 6 5 c h i l d r e n h ave im p a ir e d h e a r in g fo r b o th h i g h an d lo w t o n e s , due to c h r o n i c s u p p e r a t i v e o t i t i s m e d i a , o t o s c l e r o s i s , and s o f o r t h .

**• S . J . Crowe a n d , C u r t i s F . Burnam; "The R e c o g n i t i o n , T r e a t m e n t , and P r e v e n t i o n , o f H e a r i n g I m p a i r m e n t s i n C h i l d r e n A n n a l s o f O t o l o g y , R h i n o l o g y , and L a r y n g o l o g y , 5 0 : 2 1 - 2 2 , Mar m

r ~

------------------------------------------------ -------------------------------------

12 2 4)

th a t s e v e n -te n th s (7 /1 0 ) o f th e g i r l s have g o o d h e a r i n g f o r a l l t o n e s bu t o n l y a b o u t o n e - h a lf ( 1 /S ) o f t h e b o y s bave good h e a r in g fo r a l l to n es.

5)

t h a t a p p r o x im a te ly , o n e - h a lf ( 1 /S ) o f th e 1 5 6 5 c h i l d r e n h a d h a d t h e i r t o n s i l s and a d e n o i d s r em o v ed a t t h e v a r i o u s h o s p i t a l s i n B a lt im o r e , b u t th e i n c id e n c e f o r im p a ire d h e a r i n g f o r h i g h t o n e s w as a b o u t t h e same i n t h i s g r o u p a s i n t h e c h i l d r e n who h a d had no o p e r a tio n .

One o f t h e i m p o r t a n t r e a s o n s f o r t h e d e t e c t i o n o f im ­ p a ir e d h e a r in g

as e a r ly in th e age o f th e

e v en th o u g h t h e d e f e c t a sso c ia te s

is

fo r th e

is

not n o tic e a b le

c h ild a s p o s s ib le to th e c h ild

p rim a ry p u rp o se o f e f f e c t i n g

or h is

su ccess­

f u l t r e a t m e n t w h i c h d e p e n d s on t h e f o l l o w i n g : 1)

T he h e a r i n g im p a ir m e n t m u s t b e r e c o g n i z e d an d t r e a t m e n t b e g u n i n t h e e a r l i e s t s t a g e .

.

.

2)

T he t y p e a m en d a b le t o t r e a t m e n t i s s e c o n d a r y t o c h a n g e s i n t h e jgiid dle e a r m u s o s a , w h ic h im p a ir t h e m o b i l i t y o f th e o s s c u la r c h a in .

3)

The e a r can n ot f u n c t i o n n o r m a lly i f t h e r e i s any in t e r f e r e n c e w ith th e v e n t i l a t i o n o f t h e m id d le e a r . No m a t t e r w h a t i s t h e p r i m a r y c a u s e o f t h e d e a f n e s s , make e v e r y e f f o r t t o k e e p t h e E u s t a c h ia n t u b e s open and f u n c t i o n ­ i n g n o r m a lly .

4)

I t m u s t b e rem em b ered t h a t c h i l d r e n h a v e n e a r l y a l l o f th e v a r io u s ty p e s o f d e a fn e ss seen in a d u lt s and th a t a l l o f t h e s e ty p e s have i n t h e i r e a r l y §ta§@ o n e sym ptom i n common— i m p a i r e d h e a r ­ in g f o r iiig h t o n e s w it h good h e a r in g f o r lo w t o n e s . T h e r e fo r e , i t i s not p o s s ib le t o r e s t o r e th e h e a r in g or s to p th e p r o g r e ss of d e a fn e ss in

123

e v e r y c h ild w ith l o s s o f h e a r in g fo r h ig h t o n e s . •*In t h i s stu d y i t c h i l d r e n w h ose t o n s i l s th e

was fou n d t h a t

75 p e r c e n t o f t h e

and a d e n o id s h ave b e e n rem oved b e f o r e

a g e o f p u b e r t y , h a v e a r e c u r r e n c e o f t h e s e g r o w t h s , and

th a t

th e y i n t e r f e r e w ith t h e v e n t i l a t i n g

E u sta c h ia n tu b e , ness.

2

fu n c tio n of th e

and c o n s e q u e n t l y l e a d t o

M ost o f t h i s

n iz e d e a r l y enough.

p r o g r e ssiv e d e a f-

d e a f n e s s may be c u r e d i f

it

is

recog­

D r . G-eorge M o r r i s o n C o a t e s s a i d

in

a d d r e s s i n g t h e P h i l a d e l p h i a C o n v e n tio n t h a t t h e m ost s p e c ­ t a c u l a r and i n t e r e s t i n g

w ork i n t h e 7 4 y e a r s o f t h e h i s t o r y

o f o t o l o g y i n A m e r ic a w a s i n t h e iv e

a m e lio r a tio n o f p r o g r e ss­

d e a fn e ss by s u r g i c a l tre a tm en t. C a m p b e ll r e p o r t s

g r e ssiv e

c a s e s o f o p e r a tio n f o r c h r o n ic prok

d e a f n e s s on 1 3 p a t i e n t s i n w h ic h t h e

im p r o v e d fr o m o v e r 1 4 t o

h e a r in g

a c u ity

3 5 . 7 d e c i b e l s d u r i n g a 1 0 -m o n th

p e r io d , th e average b e in g 2 1 .8 d e c ib e ls

i n im p r o v em e n t.

3- S . J . Crowe a n d - C u r t i s F . Burnam , "The R e c o g n i t i o n , T r e a tm e n t , and P r e v e n t i o n o f H e a r in g Im p a ir m e n t i n C h i l d r e n . " A n n a ls o f O to lo g y , R h in o lo g y and L a r y n g o lo g y , 5 0 : 2 3 - 2 5 , M a rc h , 1 9 4 1 . 2 I b id . p. 17. ® Edward H. C a m p b e ll , "The E v a l u a t i o n o f t h e L a b y r i n t h F e n e s t r a t i o n O p e r a t i o n f o r C h r o n ic P r o g r e s s i v e D e a f n e s s . " L a r y n g o s c o p e , 5 1 : 1 0 1 7 - 1 0 1 9 , N ovem ber, 1 9 4 1 .

It

h a s been s a i d t h a t u n le s s t h e r e

le a s t te n d e c ib e ls a fte r

or n o c o n s e q u e n c e .

m en t o f f r o m 5 t o 1 0 d e c i b e l s i s

t h e v a r io u s t e s t s w ere m ade.

sary.

T h e r e f o r e , tw o o r m ore t h o r o u g h In th e

an im p r o v e m e n t o f 30 d e c i b e l s i s

L o s s e s o f 50 d e c i b e l s

c r itic a l n eces­

o r m ore make im p r o v e m e n t o f h e a r ­

in g an u n c e r t a in t y .

I f th e

l a s t s l e s s th a n f iv e

y e a r s, th e

su c c e s sfu l.

t h a t e x t e n t a t t h e tim e

s h o u l d p r e c e d e an o p e r a t i o n .

sp eech fr e q u e n c ie s,

An i m p r o v e ­

c o n s i d e r e d o f no i m p o r t a n c e

a u d i o m e t e r i t s e l f may v a r y t o

a u d io m ete r t e s t s

a n im p r o v e m e n t o f a t

t r e a t m e n t , t h a t t h e . im p r o v em e n t

ca n be reg a r d e d a s o f l i t t l e

a s th e

is

im p r o v e m e n t a f t e r t h e o p e r a tio n i s

o p e r a tio n

c o n s i d e r e d un­

tfNo t h e r a p y o f d e a f n e s s i s w a r r a n t e d w h e r e t h e r e

i s a n y t h i n g m o re t h a n an o u t s i d e c h a n c e o f f u r t h e r im p a ir m e n t or i f

t h e u lt im a t e u se of a h e a r in g a id i s

je o p a r d iz e d .

s h o u ld a tr e a t m e n t be u se d w h ic h w i l l o b v i a t e t h e o f a m ore e f f e c t i v e

p r o c e d u r e .”

e s p e c i a l l y im p o r ta n t a f t e r th e

Nor

p o s s ib ility

R ep ea ted e x a m in a tio n s a re o p e r a tio n h a s b een p erfo rm ed .

T he i d e a l m e d i c a l o r s u r g i c a l t r e a t m e n t s h o u l d b e p e r m a n en t a lth o u g h , e ffect

nAt t h e p r e s e n t t i m e i t

i s p r o b a b ly im p o s s ib le t o

an a c t u a l c u r e o f d e a f n e s s b y a n y m e a n s a v a i l a b l e . ” ^ S u c c e s s f u l t r e a t m e n t may o f t e n be a c c o m p l i s h e d b y t h e

rem oval o f e n la r g e d t o n s i l s

1

and a d e n o i d s , b y o c c a s i o n a l i n -

W a l t e r H u g h so n and L* G-. W i t t i n g ,

o£.

c i t . , pp.

3 8 1 -38 3.

125 f l a t i o n t o rem ov e t h i c k m ucus i n t h e t u b e and t h e m i d d l e e a r , and by g e n e r a l h y g e n ic m e a s u r e s r e l a t i v e change o f

c lim a te

and t r e a t m e n t

to d i e t ,

of a lle r g ic

v ita m in s,

te n d e n c ie s,

and

e v e r y t h i n g t h a t w i l l im p r o v e t h e h e a l t h o f t h e c h i l d a n d l e s ­ sen th e freq u en cy o f tiv e

c o ld s.

R a d ia t io n h a s b e e n fou n d e f f e c ­

i n r e d u c i n g o b s t r u c t i n g n o d u l e s o f l y m p h o id t i s s u e ,

d e c r e a s i n g m ucus s e c r e t i o n s ,

and i n

fu n c tio n of t h e E u sta c h ia n t u b e s . ^

r e s t o r i n g th e v e n t i l a t i n g H ow ever,

it

has not been

fo u n d s u c c e s s f u l i n t h e t r e a t m e n t o f c h r o n ic m id d le e a r , for

in

or

in n e r e a r or n e r v e d e a f n e s s . THE HEW YORK TEST OF SCHOOL CHILDREN I n 1 9 4 0 , a c o m m i t t e e w as a p p o i n t e d b y t h e P r e s i d e n t

of

t h e B o a r d o f E d u c a t i o n and t h e New Y o r k Academy o f M e d i c i n e i n New Y ork t o

stu d y th e h a r d -o f-h e a r in g sc h o o l c h ild r e n in

New Y o r k C i t y .

E x te n siv e

a u d io m eter t e s t s

g iv e n t o

s u r v e y s w ere m ade, and 3 0 ,5 9 2 ,

c h i l d r e n s e l e c t e d a t random f r o m

s c h o o ls r e p r e s e n t in g th e e le m e n ta r y , v o c a tio n a l sc h o o ls. procedure.

It

o f any s i m i l a r

is

4-A

j u n i o r h i g h , h i g h , and

T h e s t u d y w as made w i t h t h i s o u t l i n e

of

v e r y t h o r o u g h , and m i g h t s e r v e a s a g u i d e

stu d ys

1 S. J. Crowe and Curtis E. Burnam, o£. cit., pp. 25-31.

126

10

S t u d i e s o f t h e i n o i d e n c e on t h e b a s i s o f group a u d io m eter t e s t s .

2)

S t u d ie s o f in c id e n c e f o r e d u c a t io n a l and m e d i c a l p u r p o s e s on t h e b a s i s o f p i t c h to n e a u d io m ete r t e s t s .

3)

S tu d ie s o f o t o l o g ic a l n eed s th ro u g h a c tu a l o t o l o g i c a l e x a m in a tio n s by a c o m m ittee o f o to lo g is ts.

4)

A d e t a i le d stu d y of h e a r in g t e s t s , o t o l o g i c a l f i n d i n g s and c a s e r e c o r d s o f P u b l i c S c h o o l 4 7 , New Y o r k , i n c l u d i n g o t o l o g i c a l e x a m i n a t i o n s o f a s a m p le o f a p p r o x i m a t e l y 5 0 c h i l d r e n , and a p it c h to n e t e s t o f ev ery sc h o o l c h ild .

5)

S tu d ie s o f sp ee ch , e d u c a tio n a l a c h iev e m en t, p e r s o n a l i t y and e m o tio n a l a d j u s t m e n t s o f a c o u s t i c a l l y h a n d ic a p p ed c h i l d r e n , e i t h e r d e a f or h a r d - o f - h e a r i n g .

6}

A s tu d y o f t h e u n o f f i c i a l com p en satory edu­ c a t i o n a l program p r o v id e d f o r t h e h a r d - o f h e a r i n g c h i l d r e n i n th e s c h o o l s t h r o u g h o u t t h e c i t y u n d er t h e s p o n s o r s h ip o f t h e Board o f E d u c a t i o n , o p e r a t e d b y t h e W. p* A .

7)

A f o l l o w - u p o f g r a d u a t e s o f P u b l i c S c h o o l 47 M a n h a t t a n , t h r o u g h q u e s t i o n n a i r e s and v i s i t s t o h o m e s , h i g h s c h o o l s and v o c a t i o n a l s c h o o l s .

8)

A s t u d y o f e q u ip m e n t a v a i l a b l e and u s e d f o r l i s t i n g h e a r i n g f o r a c o u s t i c and a u r i c u l a r tr a in in g . ^ Of t h e

2 ,5 4 6 c a s e s

v e a le d lo s s e s - in

s h o w in g i m p a i r m e n t , 1 , 2 2 4 r e ­

one or' b o t h e a r s .

T h ese w ere g iv e n t h e

2 -A and 6-A i n d i v i d u a l a u d i o m e t e r t e s t s ,

and o f t h e s e

1080

W e s t l e y M. H u n t," "What i s B e i n g Done f o r t h e D e a fn e s s o f S c h o o l C h ild r e n ," L aryngoscope, 5 2 :2 3 0 -2 3 1 , M arch, 1 9 4 2 .

127

su b m itted t o in to

six

an o t o l o g i c a l e x a m i n a t i o n .

g r o u p s a c c o r d in g t o th e

T h ese w ere d i v i d e d

d e g r e e o f h e a r in g l o s s .

Each d i v i s i o n

is

tio n te ste d .

On t h e b a s i s o f t h e f i n d i n g s o f t h e

a u d io m ete rs, th e groups:

r e p r e s e n ta tiv e o f th e e n tir e

1080 c h ild r e n t e s t e d

fa ll

c la s se s*

in d iv id u a l

in to th e fo llo w in g

1) T hose 2 8 8 , h a v in g 2 0 -5 9 db . l o s s

e a r w ere p la c e d i n l i p - r e a d i n g

s c h o o l p o p u la ­

2)

in th e

b etter

The 8 , h a v i n g

a 60 d b , o r m ore l o s s

i n b o t h e a r s w ere g iv e n l i p - r e a d i n g

p lu s s p e c ia l tr a in in g

or c o a c h in g .

l e s s t h a n 20 d b . l o s s ,

or 1 5 -1 9 ,

lip - r e a d in g , p lu s h e a r in g a id 4}

5)

T hose 5 9 , h a v in g

i n b o th e a r s , w ere g i v e n

and p e r h a p s s p e c i a l c o a c h i n g .

T h o s e 5 9 , h a v i n g l e s s t h a n 20 d b . i n t h e

b etter ea r,

and

2 0 -6 0 in t h e w orse e a r , w ere c o n sid e r e d s p e c i a l c a s e s n eed ­ i n g s p e c i a l h e a r i n g e q u ip m e n t 248,

10 -1 4 db.

and s p e c i a l t e a c h i n g .

in th e b e tte r e a r ,

1 0-60 in th e

5 | The

w orse e a r ,

w ere g i v e n s p e c i a l s e a t i n g and l i g h t i n g a r r a n g e m e n t, and The 5 4 4 h a v i n g 1 - 5 d e c i b e l l o s s i n th e w orse 1,

5,

e a r , w ere g iv e n

in th e b e tte r

a r e few s c h o o l c h ild r e n w ith s e v e r e c a s e s 60 d e c i b e l s o r m ore i n b o t h e a r s , m al h e a r in g ,

e a r , and 5 -6 0

s p e c ia l c o n sid e r a tio n .

and 6 c o n t a i n t h e l a r g e s t n u m b er.

G rou p s

T h i s sh o w s t h a t t h e r e of im p a irm e n t, 8 w i t h

and f e w w i t h a c u t e

59 h a v i n g l e s s t h a n a 20 d b .

6j

or n o r ­

lo s s in b o th e a r s.

The o n e s h a v i n g 60 o r more d e c i b e l l o s s a r e p r o b a b l y i n t h e

sc h o o ls fo r th e d e a f.

1

T h e ..f a c t o r s w h ic h w ere fo u n d t o th e o to lo g ic a l

be c o n t r i b u t i n g t o

c o n d itio n w ere a s - f o l l o w s : ;

1.

P resen ce of d ise a se d t o n s i l s or b o th , 405 c a s e s .

2.

S in u s i n f e c t i o n ,

3.

Lymph t i s s u e ,

4.

T u r b in a te p a t h o lo g y ,

5.

D e v ia te d o b s t r u c t in g s e p t a .

or a d e n o i d s ,

199 c a s e s .

190 c a s e s . 1 89 c a s e s .

T h is s tu d y i n d i c a t e s t h a t t h e r e i s le m o f h e a r i n g im p a ir m e n t ta tio n

a d e fin ite prob­

in t h e p u b lic s c h o o ls in th e adap­

o f t h e a c o u s t i c a l l y h a n d ic a p p ed t o t h e i r p h y s i c a l t e a c h ­

in g su r r o u n d in g s, t h e n e c e s s i t y o f o t o l o g i c a l e x a m in a tio n s o f sc h o o l c h ild r e n ,

and th e

im p o r ta n c e o f p r e v e n t i t i v e m e a s u r e s

i n e l i m i n a t i n g t h e num ber o f c a s e s o f i m p a i r m e n t . THE MINNEAPOLIS STUDY Howard A . G a r t e r r e p o r t s t h e t e s t s c h ild r e n in

i n M in n e a p o lis w it h th e

c lin ic a l p r a c tic e .

o f 1 0 ,0 0 0

sch ool

pure t o n e a u d io m ete r u sed

He f o u n d t h a t

among s c h o o l c h i l d r e n

l o s s f o r t h e h i g h e r t o n e s w a s f r o m tw o t o t h r e e t i m e s a s g rea t as d e f ic ie n c ie s of th e

lo w e r f r e q u e n c i e s , and t h a t t h e

phonograph a u d io m ete r f a i l e d t o

1 i b i a • p* 2 3 s -

sh o w 50 p e r c e n t o f h e a r i n g

129 lo sse s.

1 C h ild r e n w ith h e a r in g l o s s e s w ere c l a s s i f i e d

to th e age o f th e c h ild o f th e l o s s ,

a t th e tim e o f th e l o s s ,

a c c o r d in g

t h e am ount

and s u c h v a r i a b l e s a s e n v i r o n m e n t , p e r s o n a l i t y ,

an d i n t e l l i g e n c e .

A c co r d in g to M i l l e r ,

as h a r d -o f-h e a r in g , p a r t i a ll y d e a f,

c h ild r e n are grouped

and d e a f .

^ T h e-h a rd -o f

h e a r in g are th o s e h a v in g a h e a r in g l o s s

o f 20 d e c i b e l s i n

b oth e a r s .

lip -r e a d in g .

p a r tia lly

T hey r e q u i r e

The

d e a f a r e t h o s e who h a v e en o u g h h e a r i n g t o d e v e l o p

some s p e e c h , r e q u ir e

in s tr u c tio n in

e v e n th o u g h i t

s p e c ia l tr a in in g

may b e i m p e r f e c t .

T hose c h i l d r e n

in la n g u a g e, lip - r e a d in g ,

an d s p e e c h

a s w e l l a s i n d i v i d u a l h e lp w ith a l l o t h e r s c h o o l s u b j e c t s . T h ey s h o u l d b e a s s o c i a t e d a s much a s p o s s i b l e c h ild r e n .

As much o f t h e work a s p o s s i b l e

w ith h e a r in g

sh o u ld be ta k e n

in th e p u b lic s c h o o ls w ith c h ild r e n o f norm al h e a r in g .

Group

h e a r i n g a i d s a r e o f g r e a t v a l u e to t h e s e c h i l d r e n . ” % THE SAN FRANCISCO STUDY O ver a p e r i o d o f on th e s c h o o l c h ild r e n

1 I b id , pp.

ten y e a r s,

th ree

su r v e y s w ere co n d u cted

o f San F r a n c is c o .

T h er e w e r e 8 6 , 0 0 0

2 3 0 -2 3 8 .

^ A l f r e d Lewy and Norman L e s f a in , o p . c i t . .

p. 471.

130 c h ild r e n

e x a m in e d i n a l l ,

h ig h s c h o o l g ro u p s. in g ,

in c lu d in g gra d es 4 th rou gh ou t th e

The 4 - A a u d i o m e t e r w as u s e d i n t h e

test­

and t h o s e s h o w i n g i m p a i r m e n t s w e r e t e s t e d w i t h t h e 2 - A .

The f i r s t

su rvey

in c lu d e d 3 6 ,1 9 1 c h ild r e n .

Of t h e s e ,

3 ,4 2 7 ,

o r 9 . 5 p e r c e n t sh o w e d h e a r i n g l o s s e s o f 9 d e c i b e l s o r m ore i n th e b e t t e r e a r .

The s e c o n d s u r v e y w as made f i v e y e a r s

l a t e r t e s t i n g 1 9 ,6 2 7 s c h o o l c h ild r e n , c e n t sh ow ed a l o s s o f 9 d e c i b e l s . of t e s t s ,

th e c h ild r e n o f t h i s

and 1 , 4 3 3 ,

As a r e s u l t

or 7 .3 per

of th ese s e r ie s

sc h o o l system m a n ife ste d a

m a rk ed d e c r e a s e o f p r o g r e s s i v e im p a ir m e n t a s w e l l a s a d e c l i n e i n t h e number o f d i s c h a r g i n g e a r s ,

in fe c te d

to n s ils ,

and com­

m u n ic a b le d is e a se s.^ * D u r i n g th e p a s t f i v e much t h r o u g h l e g i s l a t i o n

y e a r s , New York S t a t e h a s d o n e

c o n c e r n in g th e c o n s e r v a t io n o f h e a r ­

i n g b y m a k in g p h y s i c i a n s , n u r s e s , r e p o r tin g th o s e under s ix y e a r s of h e a r in g was im p a ir e d . io m e tr ic

te s tin g of a ll

com p eten t p e r s o n t o

and p a r e n t s r e s p o n s i b l e

fo r

a g e who w e r e d e a f o r w h o s e

L e g is la tio n a lso sch o o l c h ild r e n ,

in c lu d e d ann ual aud­ a p p o in tm en t o f a

s u p e r v i s e a l l t e s t s and t h e i n s t r u c t i o n

o f s t u d e n t s i n n o r m a l s c h o o l s c o n c e r n i n g t h e m e t h o d s o f m a k in g

1 J . 0 . G e i g e r , a n d F . H . R o d i n , "The P r o b le m o f t h e E a r d - o f - H e a r in g S c h o o l C h ild * A r c h iv e s o f P e d i a t r i c s , 5 6; 6 0 5 , S ep tem b er, 1 9 3 9 .

131 su ch t e s t s .

1

C on rad G. S e l v i g , la tio n

c h a ir m a n o f t h e c o m m i t t e e o n l e g i s t

f o r t h e h a r d o f h e a r i n g o f t h e A m e r ic a n S o c i e t y f o r

t h e H ard o f H e a r i n g , h a s o u t l i n e d t h e f o l l o w i n g p r o g r a m f o r sta te le g isla tio n : 1.

C o m p u lso r y h e a r i n g t e s t s f o r a l l c h i l d r e n a t r e g u la r i n t e r v a l s by com p eten t s c i e n t i f i c m eth o d s.

2.

P r o p e r m e d i c a l f o l l o w - u p t r e a t m e n t and c a r e f o r a l l i n n e e d , and i n s t r u c t i o n s t o p a r e n t s a s to i t s n e c e s s i t y .

3.

R e m e d i a l i n s t r u c t i o n i n t h e fo r m o f l i p - r e a d i n g fr o m p r i m a r y g r a d e t h r o u g h c o l l e g e . S p e c ia l t r a i n i n g i n s p e e c h , and v o i c e w here n e c e s s a r y . Group h e a r i n g a i d s i n e v e r y s c h o o l w h e r e t h e r e a r e f i v e o r m ore h a r d o f h e a r i n g c h i l d r e n .

4.

V o c a tio n a l g u id a n c e.

5.

A d u lt c l a s s e s i n l i p - r e a d i n g s e r v in g th e h a r d o f - h e a r i n g i n a l l c o m m u n ities i n t h e s t a t e .

6.

A s s is t a n c e to th e h a r d - o f - h e a r in g in se a r c h o f e m p lo y m en t and a f a i r d e a l u n d e r C i v i l S e r v i c e r u le s.

7.

A f u l l - t i m e d i r e c t o r o f w ork f o r t h e h a r d - c f h e a r i n g on t h e s t a f f o f t h e S t a t e D e p a r tm e n t o f E d u c a tio n .

8.

T r a in in g c o u r s e s f o r te a c h e r s o f th e h a r d -o fh e a r in g i n e v e r y S t a t e T eachers* C o lle g e . & .>

* S

1 H o ra ce H ew h a rt, " P r o g r e s s i n t h e C o n s e r v a t io n o f H e a r in g ." A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y . 50 : 1 3 3 , MarcH,' IS ^ T T 2

Lewy and Leshin, op. cit., pp. 465-466*

132 F o r y e a r s O regon h a s had a v e r y e la b o r a t e program o f te s tin g

s c h o o l c h i l d r e n b a s e d on t h e

th a t s ta te

as w e ll as th o se of o th er s t a t e s .

p h y s i c i a n and t h e d ia g n o sis,

The s c h o o l

s c h o o l e x a m i n e r c h e c ic e e a c h c h i l d a s t o

treatm en t p r o g n o s is ,

from tim e t o in to

form er e x p e r ie n c e s o f

tim e .

and c l a s s r o o m a d j u s t m e n t

C h ild r e n w it h im p a ir m e n ts a r e d i v i d e d

f o u r c l a s s e s a c c o r d i n g to t h e f o l l o w - u p w ork n e e d e d .

T he c o n s u l t a n t

i n h e a r i n g and v i s i o n

su p e r in te n d e n t o f s c h o o ls , c a tio n personn el fo r

the

1

c o l l a b o r a t e s w i t h th e

l o c a l h e a l t h o f f i c e r , h e a l t h edu­

c o n s e r v a t io n o f h e a r in g i n co m m u n ities.

"Warren E . G a r d n e r , P h . D . , C h airm an o f t h e C o m m itte e on t h e H a rd o f H e a r i n g o f t h e A m e r ic a n S o c i e t y f o r t h e H a rd o f H e a r in g , i n h i s

r ep o rt fo r th e s c h o o l y ea r 1 9 3 8 -1 9 3 9 ,

s t a t e s th a t th e l,8 7 ip 0 0 in 767 c i t i e s b le

c h i ld r e n w ere g iv e n a u d io m e te r t e s t s

and t o w n s and 1 2 5 c o u n t i e s .

g a in over p r e v io u s y e a r s .

was 5 9 0 ,0 0 0 .

a rem arka­

The num ber i n Hew Y ork S t a t e

M a ssa c h u s e tts gave 1 8 0 ,0 0 0 t e s t s

and o n e c o u n t y j C a l i f o r n i a , 1 5 5 t e s t s c o u n tie s.

T h is i s

i n 171 tow n s

i n 4 2 t o w n s an d 9

I n P e n n s y l v a n i a , w h e r e t h e S t a t e D e p a r tm e n t o f

E d u c a t i o n tw o y e a r s ago p u r c h a s e d 4 7 a u d i o m e t e r s t o b e l o a n e d t o s c h o o l u n i t s w h i c h d i d n o t own t h e e q u i p m e n t , 1 0 7 , 0 0 0 w e r e te sted la s t year.

I n d i a n a and O klahom a e a c h t e s t e d 7 0 , 0 0 0 .

The W. P . A . s u r v e y s i n O h io and o n e c o u n t y i n I l l i n o i s

^ Ibid. pp# 466-467.

ao co u n t-

133 f o r 1 4 0 ,0 0 0 *

T ills i s

and l a r g e r c i t i e s ,

a fin e

b e g in n in g ,

b u t i n many s t a t e s

t h e p r o c e d u r e i s p r a c t i c a l l y u n k n ow n .

Tbe

i n c i d e n c e o f a s i g n i f i c a n t h e a r i n g l o s s w as b e t w e e n s i x a n d s e v e n p e r c e n t w i t h w i d e e x t r e m e s d e p e n d e n t on many v a r i a b l e fa cto rs.

^

SUMMARY.

Xn a s much a s t h e r e w ere no r e l a t e d s t u d i e s

on h e a r in g f o r s t e n o g r a p h e r s , s u r v e y s and s c h o o l t e s t s f a c t s im p o rta n t to th e

it

was d e c id e d t o r e v ie w r e c e n t

i n an e f f o r t t o

s a m p l i n g o f t h e s t u d y w as s m a l l ,

o n e s r e v ie w e d p r e s e n t e d b oth i n t e n s i v e

p r o c e d u r e and th e r e s u l t i n g and s i m i l a r

t h e new

S in c e th e

t h e c o n c l u s i o n s drawn w o u ld

h a v e t o b e b a s e d on t h e d a t a o f l a r g e

and n u m b ers.

fo r th e se

th e fo r m u la tio n o f

e s tim a tin g p e r c e n ta g e h e a r in g l o s s .

in b oth v a r ie t y

s ig n ific a n t

stu d y under c o n s id e r a t io n ,

s t u d ie s h e lp e d to fu r n ish d a ta f o r m e th o d f o r

secu re

s u r v e y s and t e s t s a s t h e and e x t e n s i v e

stu d ie s

C o n s e q u e n tly , th e m eth od s o f d a t a w o u ld b e s i g n i f i c a n t t o

th is

s t u d ie s in a u d io m e tr ic t e s t i n g .

T he m o s t i m p o r t a n t

s t u d i e s p r e s e n t e d w h ic h h a v e made

v a lu a b le c o n tr ib u tio n s to th e p r e sen t

s t a t u s o f our k n o w led g e

o f h e a r i n g and h e a r in g s t a n d a r d s a r e t h e U n it e d S t a t e s B u b lic H e a lth S e r v ic e S u rv e y ,

th e New Y ork and San F r a n c i s c o W o r ld ’ s

F a i r s ’ T e s t s , t h e J o h n s H o p k in s H o s p i t a l S t u d y , t h e New Y ork T e st o f S c h o o l C h ild r e n ,

th e M in n e a p o lis S tu d y ,

th e San F ran­

c i s c o S t u d y , and t h e r e p o r t o f t h e A m e r ic a n S o c i e t y f o r t h e H a rd o f H e a r i n g .

^-Horace Kewhart, o p . p i t , , p . 1 -3 3 .

CHAPTER VI RELATED INVESTIGATIONS A r e v ie w o f th e to

a v a ila b le

lite r a tu r e

and i n q u i r i e s

s t a n d a r d s a s s o c i a t i o n s and a u t h o r i t i e s on h e a r i n g and

h e a r in g a id s

i n d i c a t e d t h a t t h e r e w ere n o a v a i l a b l e

on h e a r in g a s i d e from t h o s e o f m i l i t a r y

se r v ic e s.

sta n d a rd s A lth o u g h

v a r io u s t y p e s o f h e a r in g s ta n d a r d s w ere u se d by o r g a n i z a t i o n s , m any o f th e m w e r e n o t b a s e d on s c i e n t i f i c

te s tin g

w ere n o t a c c e p te d a s sta n d a r d s by a u t h o r i t i e s , even s t r i c t l y

adhered t o

h e a r in g sta n d a r d s f o r

d e v ic e s and

and w e r e n o t

by t h e o r g a n i z a t i o n u s i n g them*

th e a c c e p t a n c e ,

d is a b ility

r a tin g ,

The and

d i s c h a r g e i n t h e m i l i t a r y s e r v i c e s and i n i n d u s t r y a r e a s fo llo w s: Navy:

F or th e w h isp e r e d v o ic e 1 5 / 1 5 t h s i n e a c h e a r , and d u r i n g g e n e r a l s e r v i c e t h e h e a r i n g m u st n o t f a l l b e l o w 7 / 1 5 t h s (b in a u r a l) f o r c o n v e r s a tio n a l v o ic e : in th e a v i a t i o n s e r v i c e n o t b e lo w 7 / 1 5 t h s ( b i n a u r a l) f o r th e w h is p e r e d v o i c e , (T h e n u m e r a t o r i n d i c a t e s t h e d i s t a n c e t h e s o u n d i s h e a r d , a n d t h e d e n o m in a t o r i n d i c a t e s t h e d i s t a n c e t h e n o r m a l e a r h e a r s t h e sam e sound under th e n o is e c o n d itio n e x i s t i n g in th e e x a m in in g r o o m ,) For p e r s o n n e l dards are not h e a r in g o f a l l on p r o m o t i o n ; on p r o m o t i o n ,

REGULAR ARMY:

a lr e a d y i n th e s e r v i c e t h e s e s t a n ­ so r i g i d l y ad h ered t o , b u t th e o f f i c e r s i s e x a m in e d a n n u a l l y a n d o f a l l e n l i s t e d men o n t r a n s f e r , a n d on r e - e n i i s t m e n t ,

F o r t h e w h is p e r e d v o i c e

135

2 0 /2 0 th s in each ear NATIONAL GUARD AND RESERVES:

For th e w hispered v o ic e

2 0 /2 0 th s in one iear and not l e s s than 1 5 /2 0 th s in the oth er FLYING CADETS; C la ss X.

For th e w hispered v o ic e 2 0 /2 0 th s in each ear

C la sse s I I and II I* each ear

At l e a s t 3 /2 0 th s in

By audiom eter C la ss I .

"An average h ea rin g l o s s n ot more .th an 15 per cent (o b ta in ed by m u ltip ly in g the averaged read in gs a t 512, 1024, 2048, by 0*8)*

C la s s e s I I and II I* No standards are s e t but q u a lif ic a t io n s are based on the w hispered v o ice and th e s o f t c o n v e r sa tio n a l v o ice t e s t s . SELECTIVE SERVICE;

Low c o n v e r sa tio n a l v o ic e i s em­ p loyed (not a w h isp e r ). (In case o f doubt u se a w a tc h .) I n s tr u c tio n s fu rn ish e d by the manu­ fa c tu r e r o f th e audiom eter may be u sed .

C la ss I - A.

For th e w hispered v o ic e

A) Normal h earin g B) 1 0 /2 0 th s or b e tte r in each ear C lass I - B. A) L ess than 1 0 /2 0 t h s , but a t l e a s t 5 /2 0 th s in one e a r . The o p p o site ear may be t o t a l l y d e a f. C la ss IV.

H earing l e s s than th e minimum p re­ sc r ib e d under I - B.

136

A ccording to th e se sta n d a rd s, the method o f e stim a tin g th e p ercen tage l o s s i s to add up the t o t a l l o s s o f a l l f r e ­ q u en cies and d iv id e by th e t o t a l number o f fr e q u e n c ie s or t e s t to n e s u sed .

T his g iv e s the t o t a l average l o s s in d e c ib e ls .

To

f in d the per cent o f l o s s , m u ltip ly the average d e c ib e l l o s s by .83 or 0 .8 . ^ Some a u t h o r it ie s u se one fig u r e and some the oth er in e s tim a tin g the p ercen tage l o s s w h ile the r e s u lt i s o fte n the same.

For years t h is method o f computing the h earin g l o s s has

been g r e a tly d isp u ted , fo r the s c a le on the audiom eter i s a lo g a r ith m e tic p ro g re ssio n w h ile the p ercen tage s c a le in which th e l o s s was s t a t e d was one o f a r ith m e tic a l p r o g r e ssio n .

Consequents

l y , the d iffe r e n c e between 20 and 30, or 1 0, was not the same on both s c a le s as th e speech range i s a ffe c te d much more s e r io u s ly at some o f the fr e q u e n c ie s than a t o th e r s .

And, depending on

th e type o f v o c a tio n a t which one i s employed, two p eop le w ith th e same amount o f h earin g l o s s working a t the same occu p ation may be d i f f e r e n t l y a ffe c te d *

The p erson w ith extrem ely h ig h or

low l o s s e s may be able to carry on h is work as w e ll as one w ith normal h ea rin g w h ile the person whose h earin g fo r speech i s a f ­ f e c t e d may have to s e l e c t a d if f e r e n t v o c a tio n a lto g e t h e r .

How­

e v e r , i n s u f f i c i e n t experim ents regarding th e im portant speech

^ Edmund F rin ee Fow ler, ^Hearing Standards fo r the Ac­ cep ta n ce, D is a b ilit y B a tin g , and D ischarge in th e M ilita r y S e r v ic e s and in In d u stry ," Laryngoscope» 5 1 :9 3 7 -9 3 8 , O ctober, 1941.

137

has made i t im p o ssib le to change th e method o f e stim a tin g p ercen tage l o s s of a u d ito r y a c u ity . The demand fo r a standard on e stim a tin g the p ercen t­ age l o s s o f h ea rin g has been so p e r tin e n t th a t a s p e c ia l com­ m issio n was appointed in 1940 to determ ine a more accu rate way o f e stim a tin g p ercen tage h earin g l o s s .

T his s p e c ia l com­

m itte e was com prised o f Drs. Bunch, Hayden, Nash, Mewhart, Sabine and Wherry.

Dr. Fowler was chairman.

O to lo g is ts and

p h y s i c i s t s d id not c o n sid e r at th a t time th a t s u f f i c i e n t ex­ perim ents had been performed to warrant s e t t i n g a standard fo r e stim a tin g p ercen tage h ea rin g l o s s .

T his a t t it u d e i s ex­

p ressed in the fo llo w in g paragraph: When one s p e c ia l f i e l d at m ed icin e comes to another w ith a c o n tr o v e r s ia l q u e stio n , as p o in te d out by Dr. Wherry, each s id e i s aware o f the d i f ­ f i c u l t i e s in v o lv e d in form u latin g a c le a r c u t, d e f­ i n i t e answer, and th e p r o fe ss io n a c c e p ts a te n ta ­ t i v e answer which may be su b ject to r e v is io n . How­ e v e r , when in d u stry comes to m ed icin e w ith a ques­ t io n on-a c o n tr o v e r s ia l s u b je c t, in d u stry w i l l be s a t i s f i e d w ith n oth in g but a d e f in it e answer. As th e q u estio n o f ear impairment and p ercen tage l o s s concerns in d u stry through th e com pensation boards, c o u rts o f law and in su ran ce com panies, th e answer g iv e n by the C ouncil and c o n su lta n ts to t h i s problem o f th e sta n d a r d iz a tio n o f t e s t s fo r h ea rin g l o s s and th e e stim a tio n of l o s s in term s o f p ercen tage must be c le a r c u t and d e f i n i t e . As t h is i s a h ig h ly con­ t r o v e r s ia l q u e stio n , in v o lv in g th e com bination of many v a r ia b le s th a t must be reduced to a common denom inator, ample d e lib e r a tio n must be given to i t b efo r e a f i n a l answer i s made. ^ 1 Pamphlet r e p r in te d from th e Journal o f the American M edical A s s o c ia t io n . 1 1 5 :8 5 4 -8 5 7 , September 7 , 1940.

138

In t h i s same rep ort o f th e Council on P h y sic a l Therapy o f the American M edical A s s o c ia tio n , emphasis was g iv e n to th e f a c t th at Dr* W illis C. B easley and Dr* Bunch con sid ered th a t the data of th e U. S* P u b lic H ealth S e r v ic e n a tio n a l h e a lth survey to g e th e r w ith th a t c o l l e c t e d at the B e ll Telephone Lab­ o r a to r ie s* a t the New York World’ s F air was s u f f i c i e n t to s e t a new standard fo r e stim a tin g p ercen tage h ea rin g l o s s . During th e p a st two y ea rs sin c e the appointment of th e com m ission, s e v e r a l methods o f computing a standard o f h ea rin g were subm itted by Dr* Bunch and Dr. Fow ler, but th e commission d id not co n sid e r th a t th ey were e n t i r e l y adequate to meet th e demand alth o u g h t.p a r ts of them were accep tab le*

Dr. Fowler pro­

posed a method which was record ed in the Journal o f th e Acous­ t i c a l S o c ie ty o f Am erica, A p r il, 1942, and Dr* Paul Sabine pro­ posed another which was recorded in T ran saction s of Ophthalmol­ ogy and O tolaryn gology, M arch-A pril, 1942*

Even though th e se

methods were very d iffe r e n t in ways of c a lc u la t io n , th e r e s u l t s were co n sid ered to be alm ost the same.

A v a r ia tio n o f the meth­

ods was p rese n te d t o th e C ou n cil on P h y sic a l Therapy o f th e American M edical A s s o c ia tio n in June, 1942, and was accep ted by the co n v en tio n .

However, a u t h o r it ie s do not co n sid e r th a t the

method p resen ted i s adequate for a l l ty p es and d egrees o f h e a r in g . The q u a n tita tiv e e v a lu a tio n o f h earin g i s o f p a r tic u la r importance in c a se s o f in su ra n ce , in s u it s fo r damages r e s u lt in g

i n j u r i e s , and o cc u p a tio n a l c h o ic e .

The c r it e r io n o f u s e fu l

h ea rin g in d u s t r ia lly i s the a b i l i t y t o hear and in te r p r e t fa m ilia r speech sou nd s, and c a lc u la t io n i s based on th e e v a l­ u a tio n o f the h a rd -o f-h ea r in g in comparison with th e normal h ea rin g in d iv id u a l.

The q u a n tita tiv e impairment of an in d i­

v id u a l depends on the e f f e c t i t has on h i s occu p ation a s w e ll as th e ordinary a f f a i r s o f l i f e .

Those who have an average

l o s s o f a c u ity o f h ea rin g o f 25 d e c ib e ls in th e important speech ran ge, 512 to 4096 d e c ib e ls , would not be m a te r ia lly handicapped in th e ordinary occu p ation s*

Those w ith an aver­

age o f 50 d e c ib e ls would be handicapped as c le r k s , salesm en, sten o g ra p h ers, or in ren d erin g p erso n a l s e r v ic e s .

A l o s s of

67 d e c ib e ls would d is q u a lif y one fo r any typ e o f work re q u irin g the a b i l i t y to understand sp eech .

In the im portant speech

range o f fr e q u e n c ie s , each ten d e c ib e l l o s s i s af lo n g er ste p toward t o t a l l o s s o f h earin g than th e p reced in g te n d e c ib e ls .^ Not o n ly i s l o s s o f h earin g an important f a c t o r , but con­ s id e r a tio n must be g iv en to th e d ista n c e o f co n v er sa tio n under which em ployees work as w e ll as to t h e ir d is ta n c e s from one a n o th er.

A stu d y was made o f th e c o n v e r sa tio n a l speech in o f ­

f i c e s , and i t was found even in la r g e o f f i c e s th a t p eo p le con-? 1 Paul 35. S a b in e, w0n E stim atin g the P ercentage Loss o f U sefu l H e a r in g ,rt T ra n sact!on s o f the American Academy o f Ophth­ alm ology and 0 1 o la r y n g o lo g y ~ pp« 179-167, Mar o n -A p ril, ±942.

140

v ersed about 46 per cen t o f the tim e w ith in f i v e f e e t from one another*

C on v ersation al speech of em ployees was d iv id e d

accord in g to d ista n c e of working c o n d itio n s o f em ployees from one another as fo llo w s ; Hear h ea rin g d is ta n c e , f i v e f e e t ; medium h ea rin g d is ta n c e , f i v e to f i f t e e n f e e t , and fa r h ea rin g d is ta n c e , f i f t e e n f e e t and more. ^ Another fa c to r o f s ig n if ic a n c e in h ea rin g i s the loud­ n ess o f the c o n v e r sa tio n a l sp eech .

P eop le do not alw ays f e e l

the same s e n s a tio n as se n s a tio n s do not correspond w ith th e amount o f th e s tim u lu s.

Ordinary c o n v er sa tio n i s u s u a lly be­

tween 30 and 60 d e c ib e ls in lo u d n e ss.

I t ta k es a g re a t d eal

o f e f f o r t and co n ce n tra tio n to understand speech at 30 d e c i­ b e l s , but c o n v er sa tio n may be c a r r ie d on w ith ease a t 60 dec­ ib e ls .

Environm ental n o ise has a grea t d ea l to do w ith the

understanding o f speech a l s o .

g

In working out th e methods fo r e stim a tin g h ea rin g l o s s , th e s e b a s ic f a c t o r s were con sid ered : 1*

The esta b lish m en t o f a base l i n e fo r the l o s s o f th e h earin g fo r sp eech . This base l i n e i s th e p o in t where a word o f a fa m ilia r lan gu age, lo u d ly spoken a t th e e a r , i s no lo n g er i n t e l l i g i b l e . T his b ase l i n e i s d e f i n i t e l y above the base l i n e o f p a in fu l s e n s a tio n .

^ Edmund P rin ce Fow ler, nA Method of Measuring the P ercen tage o f C apacity fo r H earing Speech , n Journal o f th e A c o u s tic a l S o c ie t y o f Am erica. 1 3 :3 7 3 -5 7 4 , A p r il, l94l?. 2 Paul E. Sabine,

oit., pp. 179-187.

141

2.

The second c o n sid e r a tio n i s th a t, th eim ost impor­ ta n t p a rt o f th e h ea rin g range fo r in d u s t r ia l purposes i s th at p o r tio n in v o lv ed in the h earin g of sp eech and th a t th e speech area o f an audio­ gram co vers fou n d ly th e range between 300 and 4000 c y c le s*

3*

The th ir d c o n sid e r a tio n i s th a t l o s s e s under 10 d e c ib e ls have no p a r tic u la r s ig n if ic a n c e and th a t p eo p le who do have a 10 d e c ib e l l o s s s t i l l have normal hearing*

4.

The fo u rth c o n sid e r a tio n i s t h a t , inasmuch as th er e i s a primary sp eech area which i s o f more valu e than th e secondary speech area and inasmuch as the primary area l i e s roughly between 512 and 2048 c y c le s , the p ercen tage l o s s e s should be w eighted h o r iz o n ta lly in such a fa sh io n as to g iv e more valu e to th o se occu rrin g in th e primary area than to th o se below and above it *

5.

The f i f t h c o n s id e r a tio n ta k e s cogn izan ce o f th e f a c t th a t a h ea rin g d e fe c t becomes p r o g r e s s iv e ly g r e a te r as one goes from the th r e sh o ld toward the base l in e fo r t o t a l l o s s o f i n t e l l i g i b l e speech* 1

Dr. Fowler p r e se n ts the fo llo w in g c r i t e r i a fo r m easuring th e ca p a city to hear a ir-b o rn e speech: 1* A h ea rin g t e s t fo r each ear w ith a stan d ard ized audiom eter in a sound-proofed room* . . 2.

W eighting the fr e q u e n c ie s accord in g to t h e ir impor­ tance fo r h earin g sp eech .

3* Allowance fo r the "recruitm ent* of lo u d n ess pher nomenon, which always v a r ie s in .n e r v e deafness* 4.

A means fo r e s tim a tin g the p ercen tage o f l o s s fo r b in a u ra l a s w e ll as fo r monaural d eafness*

.5*

P r o v isio n fo r changing increm ents cf l o s s in capa­ c i t y w ith s l i g h t , m oderate, and sev e re d eafness*

1 I b id , p . 191. 2 Edmund P r in c e F o w le r , Q£* c i t * , p p . 3 7 3 -3 7 4 *

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Dr# F ow ler’ s f i r s t r e q u is it e fo r m easuring the c a p a c ity to hear a ir-b o rn e speech i s a sta n d a rd ized audiom eter in a sound-proofed room.

Although, sta n d a rd ized audiom eters as ac­

cep ted by the C ouncil on P h y sica l Therapy o f the American Med­ i c a l A s s o c ia tio n i s d isc u s s e d in a l a t e r chapter* a re c e n t com­ m unication r e c e iv e d from W ilbert F# Snyder, U. S, Department o f Commerce, n a tio n a l Bureau o f Standards, r e v e a ls the fo llo w ­ ing? The th resh o ld v a lu es of the Maico D-5 audio­ m eter at t e s t to n e s o f 128, 512, 1024, 2048, and 8192 c . p . s . ( c y c le s per second) have been a d ju sted to eonform w ith v a lu e s determ ined th e 1935-1956 n a tio n a l H ealth Survey o f th e U n ited S ta te s P u b lic H ealth S e r v ic e . I t i s my understanding th a t th e se th r e sh o ld v a lu e s w i l l be adopted by the American M edical A s s o c ia tio n during t h i s month. The 705A r e c e iv e r s o f the Western E le c t r ic 6A and 6B audio­ m eters have a ls o been c a lib r a te d in term s o f t h i s th r e sh o ld . However, the audiom eters th em selves have not been a d ju ste d to th ese th r e sh o ld v a lu e s . . . I t should be added th a t t h i s Bureau has no standards fo r au d iom eters. We have a s s is t e d the American Standards A sso c ia tio n and the American M edical A s s o c ia tio n in the p rep a ra tio n o f a sta n ­ dard s p e c if ic a t io n fo r audiom eter perform ance. The C ouncil on P h y s ic a l Therapy o f th e American M edical A s s o c ia tio n has a ccep ted se v e r a l m odels of audio­ m eters which meet the requirem ents o f such s p e c i f i ­ cation # I t f o llo w s th a t accord in g to the n a tio n a l Bureau o f S tan dards, th e t e s t i n g would have to be done by the Maico D-5, or the Western E le c t r ic 6A or 6B au diom eters.

The sound­

proofed room i s id e a l f o r s c i e n t i f i c measurements and compari­

143

so n s, but i t i s alm ost im p o ssib le in mass t e s t i n g o f sch o o l c h ild r e n .

As th ere i s always a p o s s i b i l i t y of a p lu s or

minus 5 d e c ib e ls in the c a lib r a tio n o f th e audiom eter, and as th e surrounding n o is e s d i f f e r c o n sid e r a b ly , much care must be taken in c o n tr o llin g the a c o u s t ic a l c o n d itio n s of te s tin g * Even in r e l a t i v e l y q u ie t o f f i c e s , th e r e i s a wide v a r ia tio n of p o s s ib le n o is e s due to s t r e e t t r a f f i c , machinery n o is e s , con­ v e r s a tio n , f a n s , and o th er extran eou s n o is e s .

These n o is e s

may account fo r a la r g e p ercen tage o f d iffe r e n c e o f two or more audiom eter t e s t s .

Even during a s in g le t e s t , n o is e s may

vary c o n sid e r a b ly , and t h is changes th e h earin g a c u ity o f the in d iv id u a l as w e ll as p rev en ts him from h ea rin g th e sounds o f the audiom eter. The e stim a tio n o f th e s e n o is e s was made p o s s ib le by the sound l e v e l m eter which a s s i s t s in v e s t ig a t io n in numerous ways. M oises a ls o vary a t d if f e r e n t tim es o f the day; they may vary in frequency and in t e n s i t y in d if f e r e n t o f f i c e s , and a ls o in th e same o f f i c e .

Most o f the sc h o o l su rveys are made in very

q u ie t rooms or o f f i c e s w ith s p e c ia l p reca u tio n s fo r the c o n tr o l o f n o is e s ,

n e v e r th e le s s , th e most s c i e n t i f i c t e s t s are con­

ducted in sound-proofed rooms or b o o th s. The second c r it e r io n i s th at o f w eig h tin g th e freq uencies a ccord in g to t h e i r im portance fo r h earin g sp eech .

T his has been

th e most c o n tr o v e r s ia l q u e stio n in a r r iv in g at a standard o f

144

h e a r in g .

S e v e r a l methods of e stim a tin g th e im portance o f the

speech fr e q u e n c ie s have been q u ite d if f e r e n t as to th e p er­ cen tage a ssig n e d in the understanding o f sp eec h .

A fte r ca re­

f u l stu d y and d e lib e r a t io n , the fo llo w in g p ercen tages were a ssig n e d in the understanding o f th e im portant speech ton es as to t h e i r t o t a l v a lu e in the u n d erstan d in g o f sp eech .

These

sta tem en ts are Mr. Watson*s in te r p r e ta tio n s o f the ta b le s adopted by the C ouncil on P h y sic a l Therapy of the American M edical A s s o c ia tio n : The e s s e n t i a l to n es of the speech range com­ p r is e the range from 356 t o 513, from 513 to 1034, from 1034 to 3048, and from 3048 to 4096. In gen­ e r a l, the 500 c y c le freq uency range r e p r e se n ts about 15% of the im portant sounds of speech - the 1034 range r e p r e se n ts abou& 35% o f th e im portant sounds o f speech - the 3048 c y c le ran ge, the most im portant in the whole ran ge, r e p r e se n ts 30% of th e im portant sound of sp eech - the 3896 c y c le range r e p r e s e n ts about 35% o f the important sounds o f sp eech , and the 4000 c y c le range r e p r e se n ts about 5% o f the im portant sounds o f sp eech . W eighting the l o s s e s w ith th e se f ig u r e s g iv e s th e approximate v a lu e o f the a c tu a l handicap o f an in d iv id u a l* 1 A ccording to t h is w ei^ a tin g , no l o s s i s a ssig n e d f o r the f i r s t ten d e c ib e ls as t o the im portance o f speech as i t does not b eg in t o become a handicap b efore h ea rin g im pair­ ment reach es the e x te n t o f ten d e c ib e ls .

I t w i l l be n o tic e d

L. A. Watson, the Maico Company, I n c ., P erson al Correspondence, June 39, 1943,

145

th a t the fr e q u e n c ie s 1024 and 2048 are th e most im portant fo r speech as w e ll as i s the 2896 c y c le range.

L osses o f

h earin g a t th e s e fr e q u e n c ie s g r e a tly handicap a person in ca rry in g on the ordinary a f f i a r s o f l i f e depending on th e amount o f the l o s s at .each o f th e s e fr e q u e n c ie s . The fou rth e s s e n t ia l in e stim a tin g p ercen tage l o s s of

h ea rin g i s th a t o f e stim a tin g

the p ercen tage o f l o s s

fo r b in a u ra l a s w e ll as fo r monaural d e a fn e ss, or the con­ s id e r a tio n o f h earin g o f two e a r s or o f on e.

A ccording to

the new ta b le of the American M edical A s s o c ia tio n , th e b e t t e r ea r i s g iv en seven tim es as much im portance a s th e poorer e a r . T h erefo re, i f a c h ild had a l o s s as severe as f i f t y per cen t in one ea r, and normal h ea rin g in the o th e r , the l o s s o f the b e t t e r ear would be m u ltip lie d by sev en , th e l o s s o f the poor­ er ear by one, add th e two to g e th e r , and d iv id e by e i ^ i t .

The

r e s u lt would be the combined d i s a b i l i t y l o s s o f the two e a r s . A c h ild w ith a 50 per cent l o s s in one ear and normal h ea rin g in the o th er would have a combined percen tage l o s s or d i s a b i l ­ i t y r a tin g o f 6 per c e n t, which would be very s l i g h t . Bunch found th a t t o t a l l o s s o f hearin g e it h e r b i l a t e r a l or u n ila t e r a l occu rs very seldom among the c l i n i c a l p a t ie n t s which he examined.

S im ila r r e s u lt s were d u p lic a te d by Hughson,

C iocco, and Palmer who found th at 95 per cen t of the children, in th e P en n sy lv a n ia S ch ool fo r the Dea:f ’ ^respond to a t l e a s t

146

one tone in one ear by a ir c o n d u c tio n .1

T his in d ic a t e s

th a t most o f the deaf and h a r d -o f-h e a r in g can hear by some s p e c ia l means. The f i f t h fa c to r i s th a t o f daanging the increm ents of l o s s in c a p a c ity w ith s l i g h t , moderate and sev e re d e a fn e ss. The new t a b le s adopted by the American M edical A sso c ia tio n f a i l e d to make p r o v is io n fo r changing the r a t io o f l o s s encoun­ te r e d in d if f e r e n t d egrees o f d ea fn ess and the d iffe r e n c e s in d ea fn ess between the two e a r s .

They a ls o f a i l e d to make pro­

v is io n fo r d iff e r e n c e s in nerve d ea fn ess and o b s tr u c tiv e d ea f­ ness* The phenomenon of the recru itm en t o f lou d n ess fo r sounds over th r e sh o ld in a l l c a se s o f nerve d ea fn ess i s p h y s io lo g ic a lly im portant.

To th o se having nerve d e a fn e s s, loud sounds appear

to be o f g r e a te r in t e n s it y than to th o se S u ffe r in g from conduc­ tio n d e a fn e s s .

Aa do o th er neurons, th e neurons in the a u d ito r y

nerve fu n c tio n according! to the a ll-o r -n o n e law . respond a t a l l , th ey g iv e com plete r e sp o n se .

I f th e neurons

Thus, th ere i s a

recru itm en t o f se n s a tio n owing to th e a c t i v i t y o f the nerve elem ents which i s lik e w is e m a n ifested in a l l sen sory mechanisms. T his i s why in d iv id u a ls do n ot hear speech a t th e same d is ta n c e s even though t h e ir a ir -c o n d u c tio n audiograms may be e x a c tly the

^ G. C, Bunch, "Usable H earing," Annals o f O tology« B hlnology and L aryngology, 4 9 :3 5 9 , June, 1940.

147

same.

T h is phenomenon occurs a t a l l of the fr e q u e n c ie s por­

tr a y in g la ck of n eu ral resp on se except in c a se s o f t o t a l d e a fn e ss.

T his en a b les th e person having se v e r e d ea fn ess as

g rea t as a l o s s o f 60 d e c ib e ls to hear sounds which are on ly 5 or 6 d e c ib e ls over the th r e sh o ld as loud as th e ones heard 30 d e c ib e ls over the normal th r e sh o ld .

T h is i s on ly about 35

d e c ib e ls below th e in t e n s it y a t which they are heard by a nor­ mal h ea rin g ear and as much as 25 d e c ib e ls lou der than beard by a s im ila r degree o f o b str u c tio n d e a fn e ss, the exact amount depending on th e degree and typ e o f the d e a fn e s s . ^ O b stru ction d ea fn ess a f f e c t s recruitm ent because i t in ­ c r e a s e s the th re sh o ld and red u ces th e recru itm en t f a c t o r . T his i s more se r io u s than i s nerve d ea fn ess a s i t c u ts down both th e u n d esira b le as w e ll a s the d e s ir a b le sounds, and the p erc en t­ age fo r the f i r s t te n d e c ib e ls d iffe r e n c e between two ears i s u s u a lly g r e a te r than the second or th ir d 10 d e c ib e ls d iffe r e n c e between th e two e a r s .

A 10

d e c ib e l d iffe r e n c e between th e ears

shows a p ro g re ssin g increm ent of p ercen tage l o s s up to a 40 dec­ i b e l l o s s f o r the b e t t e r ear#

L osses over 60 d e c ib e ls show a

dem inishing increment o f p ercen tage l o s s , but the p ercen tage i s alw ays l e s s than a 5 d e c ib e l equal l o s s in the two ea rs excep t

3* Edmund P rin ce F ow ler, ”H earing Standards fo r A cceptance, D is a b ilit y R ating and D isc h a r g e ,in th e M ilita r y S e r v ic e s and in I n d u s tr y ,” op. c i t . , pp* 941-942.

148

when the l o s s i s over 50 d e c ib e ls , and h ere i t i s one or two d e e ib e ls g r e a te r than the 5 d e c ib e l l o s s .

In ca se s o f t o t a l

d e a fn e ss, th e in c r e a s e in p ercen tage l o s s v a r ie s from 9 per cen t when th e h ea rin g l o s s i s not below 15 d e c ib e ls to 16 per cen t when i t i s between 40 and 45 d e c ib e ls .

The p ercen tage

l o s s d im in ish es g r e a tly when i t i s g r e a te r than 45 d e c ib e ls . ^ SUMMABY.

A stu d y

of the a v a ila b le standards e x is t in g

a t the time o f th e stu d y in d ic a te d th a t th ere were no sta n ­ dards which were co n sid ered as f i n a l or c o r r e c t.

The on ly

ones in common u se and of any s ig n if ic a n c e were th o se used in the m ilit a r y s e r v ic e s , and th e s e were not s t r i c t l y adhered t o . Dr. Fowler d id not co n sid e r th e s e as c o r r e c t and proposed Others based on h is own method o f e stim a tin g p ercen tage l o s s . Even th e method o f computing h earin g l o s s e s was in d is p u te .

The

demand f o r a new method was so im p erative th a t a commission had been ap p oin ted to form ulate a new method fo r e stim a tin g p er­ cen tage l o s s in 1940.

During the en su in g in t e r v a l from 1940 to

1942, v a rio u s p la n s were subm itted by th e com m ission from tim e to tim e , but none o f them were co n sid ered adequate or f i n a l . The p la n s which provoked most thought and c o n sid e r a tio n were th o se o f Dr. C. 0 . Bunch, Dr. Paul S ab in e, and Dr. Edmund P rin ce F ow ler.

A ll o f th e s e plans were a gradual development 3* 0 . C. Bunch,

P* 379.

at

th e

149

p la n f i n a l l y adopted in June 1942 by the American M edical A sso cia tio n * The e s s e n t i a l c r i t e r i a n ecessa ry fo r the c o n str u c tio n o f a ta b le fo r e stim a tin g p ercen tage l o s s a s o u tlin e d by Dr. Fowler were b r ie f ly review ed and ex p la in ed as w e ll as were th e b a s ic f a c t o r s concerning a c o u s t ic s , h ea rin g d is ta n c e , and some o f the p e c u l i a r i t i e s o f h earin g which p a r t i a l l y ac­ counts fo r th e d i f f i c u l t y encountered in attem p ting to d e te r ­ mine a common denominator for th e c o n str u c tio n o f a ta b le fo r a c c u r a te ly e stim a tin g the v ariou s d egrees and kinds o f h e a r iis lo s s e s *

SOURCES OF DATA AND METHODS OF PROCEDURE The attem pt t o fin d the minimum l o s s o f h earin g of e f ­ f i c i e n t sten ograp h ers i s e n t ir e ly new although many p eop le have ex p ressed t h e ir in t e r e s t and t h e ir enthusiasm in th e sub­ j e c t and in r e la t e d f i e l d s ,

A review o f th e l a t e s t li t e r a t u r e

on standards o f h ea rin g in d ic a t e s a r e c o g n itio n o f th e problem and o f the commercial v a lu e o f i t s s o lu t io n as a guidance t e c n io in e lim in a tin g stu d e n ts h avin g sev ere h earin g l o s s e s from the department o f stenography* A fte r th e t i t l e was d e f i n i t e l y d ecided upon, p erson al c o n ta c ts were made w ith a u t h o r it ie s in p h y s ic s , o to lo g y , and ed u ca tio n as to the b e st method o f procedure as w e ll as conc e r a in g r e la t e d problems p e r ta in in g to th e stu d y .

Some cf

th e s e c o n ta c ts were made at th e N ation al Workshop which met a t the U n iv e r s ity o f Southern C a lifo r n ia in J u l y ,1 9 4 1 ,and in July, 1942*

A m a ilin g l i s t was a ls o made which in elu d ed th e

names o f some s e v e n t y - f iv e a u t h o r it ie s of the f i e l d s o f o t o l ­ o g y , p h y s ic s , p sy ch o lo g y , sp eech , d e a fn e ss, sten ograp h y, med­ i c a l and h ea rin g jo u r n a ls , and h earin g a id s .

Approxim ately

f o r t y - f i v e l e t t e r s were r e c e iv e d concerning the su b ject dur­ in g 1941 and 1942*

P o s s ib ly th e reason th a t th er e were few

f ' i g l l e s was due to th e f a c t th a t most o f the correspondence was conducted during th e summers as w e ll as to th e f a c t th a t th e problem

ot

h earin g was r e l a t i v e l y new and th at a u t h o r it ie s

151

did not agree on the su b je c t. Some o f the l e t t e r s which were r e c e iv e d re p resen ted the fo llo w in g o r g a n iz a tio n s:

American Standards A sso cia ­

t io n , American Bureau o f Standards, American M edical Asso­ c ia t io n C ouncil on P h y sic a l Therapy, B e ll Telephone Labora­ t o r i e s , The American S o c ie ty fo r the Hard o f H earing, Los A ngeles County Department o f H ea lth , The Maico Company, The Sonotone Company, W estern E le c t r ic Company, Johns Eopfcins H o s p ita l, Oregon S ta te Board o f H ea lth , Columbia U n iv e r s ity , Western P en n sylvan ia School fo r the D eaf, B och ester School fo r th e D eaf, School of Speech o f N orthw estern U n iv e r s ity , and L exington School fo r the D eaf, Some o f th e a u t h o r it ie s who were p a r t ic u la r ly h e lp f u l and whose names w i l l be reco g n ized as eminent a u t h o r it ie s ct t h e ir f i e l d s by th o se who are fa m ilia r w ith th e problem of h ea rin g ares

Dr, Edmund P rin ce Fow ler, Dr, Gordon B erry,

Dr, C, C, Bunch, Dr, S . J . Crowe, W ilbert F* Snyder, Dr. Warren H. Gardner, Howard A, C arter, L, A. Watson, Josep h in e T im berlahe, Dr, B, W, H agens, and Clarence D. 0*Connor, Each l e t t e r and each in te r v ie w d u p lic a te d the same respon se in d ep en d en tly in d ic a tin g th a t no one had made a s im ila r e f f o r t to fin d a standard o f h ea rin g fo r sten ograp h ers, A paragraph o f s e v e r a l l e t t e r s i s quoted in proof o f t h i s sta te m e n t:

158s

I have no knowledge of*—a study made of1 a m in i­ mum standard of h ea rin g fo r sten ograp h ers. There are s e v e r a l methods by which a standard o f h ea rin g might be ev a lu a ted for such a group* I would r e f e r you to the P relim in ary B eports o f the N a tio n a l H ealth Survey Hearing Study S e r ie s p u b lish ed by th e H. S. P u b lic H ealth S e r v ic e fo r su g g e stio n s as to methods o f e v a lu a tin g the h earin g o f s e le c t e d groups. W ilbert F. Snyder A sso c ia te P h y s ic is t N a tio n a l Bureau o f Standards Department of Commerce You have p ick ed fo r your su b je c t a very in t e r ­ e s t in g but e n t ir e ly u n in v e stig a te d f ie ld * The o n ly re sea rch you need do on i t i s s c i e n t i f i c a l l y con­ t r o l l e d te s t in g * There i s no b ib lio g ra p h y o th er than sim p le h earin g s u b je c ts on which you have p le n ty a v a ila b le in your own l i b r a r i e s . Dr. Warren K. Gardner C onsultant in H earing and V isio n Oregon S ta te Board o f H ealth I do not know o f eny h earin g t e s t s in \$iieh sten o g ra p h ers, as a group, have been the s u b je c ts o f a study* I f you wish to undertake such s t u d ie s , I th in k your b e st procedure, fo r th e p rese n t a t l e a s t , would in v o lv e th e making o f in d iv id u a l h ear­ in g t e s t s o f th e s u b je c ts with one o f the pure tone audiom eters as used by d o c to r s, ra th er than attem pt­ in g some form o f group t e s t . J . C. S tein b e rg n B e ll Telephone L ab oratories A fte r th e l e t t e r s were w r itte n fo r in form ation as to the procedure o f the study and asking fo r h e lp fu l in f o r ­ m ation from s im ila r s t u d ie s , a search was made fo r a speech or i n t e l l i g i b i l i t y t e s t which might be used in g iv in g group t e s t s to sten o g ra p h ic stu d en ts*

Although t h i s type o f t e s t

would be th e most p r a c t ic a l in a d m in istr a tio n

far

the s e l e c ­

t io n of stu d en ts in th e classroom , i t was d ecid ed th a t i t would be u n r e lia b le no m atter how c a r e f u lly co n stru cted or adm inis­ te r e d .

Some o f th e problems in v o lv e d were th o se r e la t in g to

a c o u s t ic a l c o n d itio n s o f the room in which th e t e s t was to be g iv e n , th e many extran eou s p o s s ib le n o is e s o f the classroom , a d jo in in g room, and th e o u ts id e , th e varying d is ta n c e s o f the stu d e n ts from th e te a c h e r who was g iv in g th e t e s t , the uncon­ t r o l l e d fa c to r o f sp eech of the same te a c h e r as w e ll as th a t o f d if f e r e n t te a c h e r s , th e p s y c h o lo g ic a l re sp o n ses o f stu d en ts con cern in g a t e s t o f t h i s n a tu r e , the v a r i a b i l i t y o f th e t e s t i t s e l f , and a m u ltitu d e o f s im ila r problem s.

A ll o f th e s e f a c ­

t o r s cause d if f e r e n t r e s u l t s in t e s t s and vary w ith the same in d iv id u a l from one tim e to another#

I t i s alm ost im p o ssib le to

g et even th e same r e s u lt s under th e same co n d itio n s#

Much a ls o

depends on the= one who i s a d m in iste rin g the t e s t . The a d v ice of J . G# S te in b e r g and o th ers acquainted w ith the problem in r e la t io n to. a c o u s tic s r e s u lte d in the s e le c t io n o f the audiom eter t e s t in con n ection with th e problem#

At

f i r s t i t seemed th a t the group t e s t would be b e st as i t was th e q u ick est to a d m in ister and would ta k e l e s s tim e o f th e c h ild r e n from th e r o u tin e o f th e ir c l a s s e s , b u t t h i s typ e o f t e s t i n g was a ls o im p ra ctic a l for th e s o lu t io n o f the problem as w e ll, fo r the t e s t i n g was not as r e lia b le as th at done by

15#

the c l i n i c a l audiom eter used by d octors which req u ired more tim e, but th e t e s t i n g was much more a c c u r a te . The n ex t ste p was to d ecid e upon th e group who might be t e s t e d in order to e s t a b li s h a stan d ard .

D iffe r e n t sug­

g e s tio n s were made as to the t e s t i n g o f s u c c e s s f u l sten o g ­ ra p h ers, u n s u c c e s s fu l sten ograp h ers, stu d e n ts a tte n d in g com­ m ercia l s c h o o ls , and high sch ool stu d en ts b egin n in g th e stu d y or com pleting th e study of stenography.

As th e t e s t was f o r

th e s e le c t io n o f high sch o o l s tu d e n ts, and as t h i s group would show more s im ila r it y according to th e o th er su rveys as to t h e ir h ea rin g a c u ity than would th a t o f sten ograp h ers o f vary­ in g ages as w e ll as fo r o th er r e a so n s, i t was d ecid ed th a t h ig h sch o o l stu d e n ts in th e f i r s t year o f stenography would be the most s u it a b le fo r t h i s study and fo r s im ila r t e s t i n g and s e le c t io n o f stu d en ts fo r sten ograp h y, as many stu d en ts r e a li z e t h e ir lim it a t io n s in the s u b je c ts , and as many te a c h e r s r e co g n iz e the stu d e n ts m a n ife stin g r e s t r ic t e d a b i l i t i e s o f e it h e r th e f i r s t or the second sem esters o f the f i r s t y ea ro f shorthand. In te r v ie w s were h e ld w ith the S up ervisor o f Commerce of the Los A n geles S c h o o ls, with s e v e r a l p r in c ip a ls , d ep art­ ment h ead s, and the H ealth O ffic e r o f the Los A ngeles S c h o o ls. The stu d e n ts were s e le c t e d from the Dorsey H igh 'S ch ool and th e Manual A rts Ei^h School as a r e s u lt of th e s e c o n fe r e n c e s. to th e lim it a t io n o f ty p e s of stu d en ts s e le c t e d , f i f t y were

Due

im taken from each of th e two sc h o o ls making a hundred stu d en ts used in the stu d y .

From th e Manual A rts High S ch o o l, th e

stu d e n ts were s e le c t e d who were ta k in g th e study fo r the f i r s t sem ester.

These stu d e n ts were tau gh t by th re e d i f f e r ­

ent te a c h e r s .

The te a c h e r s were taught by th re e

te a c h e r s .

te a c h e r s who were te a c h in g stenography to th e

The

d iffe r e n t

f i r s t sem ester stu d e n ts were asked to submit th e names o f t h e ir b e st as w e ll a s t h e ir w orst stu d en ts as to th e knowledge and achievem ent in the stu d y o f shorthand.

A ccord in gly, th ere

would be tw e n ty -fiv e of th e b est and tw e n ty -fiv e o f the worst stu d en ts in shorthand from th e Manual A rts High School on t i e b a s is o f t h i s s e l e c t i o n .

S tu d en ts making

co n sid ered as th e b e s t , and c la s s e d as th e

w o rst.

nAn and

th o se making "D* or

Most of the stu d en ts were

*3*! were were s ix t e e n years

o f age; many of them were sev e n te en ; some o f th e ages v a ried from f i f t e e n through seven teen and eigh teen *

The m a jo rity

were in the f i r s t sem ester o f the e le v e n th grade w h ile on ly two were in the tw e lfth grade.

There were se v e r a l r e p e a te r s ,

but most o f them were b egin n in g th e study fo r the f i r s t tim e. At th e Susan Dorsey High S ch o o l, a l l o f the stu d e n ts o f the sc h o o l who were ta k in g Stenography I I , or th o se com­ p le t in g the second sem ester o f t h e ir f i r s t year o f th e study were te ste d *

There were f i f t y of them, and a l l o f them weie

stu d y in g under the same te a c h e r .

With th e e x c e p tio n of s i x ,

a l l o f them were in the second sem ester o f the e le v e n th grade.

15f>

A ll excep t e ig h t o f the stu d e n ts in d ic a te d th a t th ey intended to he sten ograp h ic m ajors.

There were two who in d ic a te d

t h e ir in te n tio n of becoming c l e r i c a l m ajors, two planned t o major in bookkeeping, and two were ta k in g a g en era l course* One was m ajoring in Spanish; and one was m ajoring in mathe­ m a tic s.

The te a c h e r con sid ered th a t th e work h a b its o f the

m a jority o f th e stu d e n ts were a c c e p ta b le . had r e c e iv e d an

Only n in e o f them

in d ic a tin g th a t t h e ir work h a b its cou ld

be improved; two had r e c e iv e d an "g** w ith both o f t h e ir grades fo r the second sem e ster .

T hirty o f t h is group were s ix te e n

y ea rs of age; th ir te e n were sev en teen years o f age; fou r were e ig h te e n ; and th re e were f if t e e n * I t was reco g n ized th a t th e stu d y would be considered more r e lia b le i f th e stu d e n ts were o f the same I . same age, but the I .

in d exes recorded fo r the group were

v a r ia b le with a s in g le stu d e n t. and some an oth er.

and the

Some had taken one t e s t ,

C onsequently, i t was im p o ssib le t o keep

the I . Q. co n sta n t with t h i s group.

However, as the t e s t i n g

done by th e pure ton e audiom eter i s o f such a n atu re as to measure a more or l e s s p h y sic a l c a p a c ity rath er than one o f i n t e l l e c t u a l a b i l i t y , a u t h o r it ie s co n sid ered th a t th e s e v a r ia b le f a c t o r s would probably not a f f e c t th e study*

In the pure

ton© stu d y , one can e it h e r h ear the sound, or he cannot hear i t a t a ll*

I t i s even p o s s ib le to g iv e audiom eter t e s t s to

c h ild r e n as young as th ree years o f a g e, and a very s lig h t

i n t e l l e c t u a l response as nodding th e head, l i f t i n g the f in g e r , or p r e s s in g a button which l i m i t s a b u lb , i s a l l th at i s n e c e ssa r y o f th e su b je c t in making th e te s t *

These r e a c tio n s

in d ic a t e to th e t e s t e r th e in d iv id u a ls a b i l i t y to h ear the va rio u s to n es by which he i s te ste d * T his t e s t i n g was conducted by Br. W illiam Gardner, H ea lth O ffic e r of S ig h t and H earing o f th e Los A ngeles G ity Sch ools*

The a u d io m etrist under h is in s t r u c t io n , gave the

t e s t s , and an o t o l o g i s t fo llo w e d th e t e s t s s e v e r a l days l a t e r g iv in g v o ic e and o t o lo g ic a l exam inations to th o se stu ­ d en ts whose audiom eter t e s t s r e v e a le d im paired h e a r in g .

The

a u d io m e trist had been conducting th e c i t y sch o o l t e s t s f o r the p a st fo u r y e a r s .

F art of the sc h o o l week she worked in th e

c l i n i c , but most o f th e time she devoted to the t e s t i n g of sch o o l c h ild r e n o f the Los A n geles O ity S c h o o ls.

The o t o lo ­

g i s t had a p r iv a te p r a c t ic e in Los A n g eles, but he examined a l l o f th e sc h o o l c h ild r e n having d e f e c t iv e h ea rin g , and made s u it a b le recommendations to the s tu d e n ts , te a c h e r s , and to th e H ealth O ffic e r o f the h earin g impairment found in each sch o o l c h ild . As was ex p la in ed in Fart I I , Chapter 4 , under the h ead in g, *?The Audiometer,*1 th e t e s t i n g d ev ice used in t h i s stu d y was th e Maico D-5 c l i n i c a l pure tone audiom eter.

T his machine was

purchased a t the beginning o f the sch o o l year in 1941, and was

156

l a t e s t and b est c l i n i c a l audiom eter a v a ila b le • m eter o o st ap proxim ately #300,

The

The audio­

th re sh o ld v a lu e s of th e

Maico D-5 audiom eter a t t e s t to n es o f 128, 256, 512, 1024, 4096 and 8192 c y c le s per second have been a d ju sted to conform w ith the v a lu e s determ ined in the 1935^1936 N a tio n a l H ealth Survey*

The machine a ls o m eets th e requirem ents o fr th e Amer­

ica n Standards A s s o c ia tio n and the C ouncil on P h y s ic a l Ther­ apy o f th e American M edical A sso cia tio n *

The a ir^ con d u ction

t e s t was given to a l l stu d e n ts, but in c a se s o f impairment both a ir -c o n d u c tio n and bone-con d uction t e s t s were made*

The

in te r r u p te d s ig n a l was used in the b egin n in g in order to de­ term ine the th r e sh o ld v a lu e , or in order t o determ ine when ths sound was f i r s t p e r c e iv e d by the stu d en t* The su b je c t was p la c e d so th a t he could n ot see th e one g iv in g the t e s t .

Each time he heard a to n e, he nodded h is head

u n t i l h e could no lo n g er hear it *

A fte r the a u d io m etrist had

t e s t e d each tone or~frequ en cy, she recorded th e l o s s o f the in ­ d iv id u a l at th a t frequency* i s a th resh o ld t e s t .

For in s ta n c e , the audiometer t e s t

As soon a s a sound i s heard by the normal

e a r , th a t i s th e minimum in t e n s it y n e c e ssa r y to e x c it e a sen­ s a t io n , or th e minimum sound th a t may be heard by the p a r t ic ­ u la r in d iv id u a l*

A person having a l o s s w i l l have to have t h i s

to n e in c r e a se d above th e normal th r e sh o ld in order to hear i t . The amount th a t t h i s ton e i s in c r e a se d above th e th r e sh o ld in order fo r i t to be heard i s record ed as the amount o f 1he h ear-

in g l o s s .

V arious ty p e s o f impairment were reco g n ized by. the

type o f h ea rin g l o s s as w e ll as by th e o t o lo g ic a l exam in ation . A fter th e a u d io m etrist had record ed the l o s s o f th e in ­ d iv id u a l at each freq u en cy , she determ ined th e d e c ib e l l o s s . Although n ine to n es were t e s t e d , th e l o s s o f h ea rin g a t th o se to n e s most e s s e n t i a l fo r th e i n t e l l i g i b i l i t y o f speech a s proved most e s s e n t i a l fo r the i n t e l l i g i b i l i t y by the numerous author** i t i e s in the t e s t i n g o f sp eech , are* 356, 512, 1024, and 4096. The h earin g l o s s e s o f each in d iv id u a l of the group found at each o f the above t e s t to n es was record ed , and th e f i v e lo s s e s were then averaged; th e r e s u lt found was th e d e c ib e l l o s s . The H ealth O ffic e r stu d ie d th e t e s t s , and sen t the o t o l ­ o g i s t to fo llo w -u p th e audiom eter t e s t s .

The audiom eter t e s t

blanks were used by th e o t o l o g is t in record in g h is f in d in g s . The o t o l o g i s t gave th e w hisper or v o ic e t e s t to each o f th o se whom he examined who had been found to have a h earin g im pair­ ment.

He a ls o made a p h y s ic a l exam ination o f th e ea r .

H is

rep o rt was made to the H ealth O ffic e r who made a w ritten, record o f each case and sen t a copy to th e p r in c ip a l .and th e su perin ­ te n d e n t, and kept th e in d iv id u a l r e p o r ts on permanent f i l e ac­ co rd in g to th e g en era l procedure o f t e s t i n g sc h o o l c h ild r e n . Various recommendations were made to th o se m a n ife stin g im pair­ m ents, and s te p s were taken t o d ecrease th e e x te n t cf th e handi­ cap.

Sometimes ch ild r en are p la ced in s p e c ia l lip -r e a d in g ,

c l a s s e s , but no c h ild was found to have l o s s e s s u f f i c i e n t to

16©

m erit t h i s p rocedu re, but some were recommended to s i t in the fr o n t o f the sch o o l room to improve t h e i r h ea rin g a c u ity . A fter th e a u d io m etrist and th e o t o lo g i s t had made t h e ir r e p o r t s , and as soon as the H ealth O ffic e r had com pleted h i s r e p o r t, th e in d iv id u a l r e p o r ts along w ith the one made by the H ea lth O ffic e r were secu red .

A l i s t o f th e names

at

d en ts was o b tain ed from the te a c h e r s by th e w r it e r .

th e s tu ­ These s t u ­

d en ts had been ranked as "Bigjx*1 o r "low** by the te a c h e r s sub­ m it t in g th e ir names accord in g to th e grades which th e stu d en ts had made on th e su b je c t for th e f i r s t te n weeks o f th e sem ester. I t was decid ed th a t a standard shorthand t e s t would be more r e li a b l e fo r t e s t i n g sten ograp h ic e f f i c i e n c y than was th e grades a ssig n e d by the te a c h e r s , fo r the grades o f the stu d e n ts had been g iv en by a t l e a s t fo u r d iffe r e n t te a c h e r s who had d i f ­ fe r e d in methods and standards*

The t e s t s e le c t e d was a new

one d ev ised by Yernal H. Carm ichael, which was soon to be pub­ lis h e d by the Gregg P u b lish in g Company alon g w ith oth er t e s t s of th e s e r i e s .

T his s e r ie s o f t e s t s had been co n stru cted so th a t

one would be g iv en a t th e end o f each six -w ee k s p eriod and at th e end o f each sem ester fa r fou r sem ester p erio d s o f shorthand. There were s ix te e n t e s t s in a l l .

The t e s t s were e n t i t l e d

"Shorthand Learning T ests" and were very com prehensive in cover­ in g th e m a te r ia l which stu d e n ts were supposed t o have stu d ie d during th e p e r io d o f time fo r which th ey were c a r e f u lly d esig n ed .

I t was a ls o co n sid ered th at as th e r e would he no f u r ­ th er op p ortu n ity to con tact th e stu d e n ts during the sem ester, th a t i t might prove valu able to g iv e th e stu d e n ts a q u e stio n ­ n a ir e p rim a rily to f in d out th e h is t o r y o f any h earin g im pair­ ments which might be d isco v ered on the h earin g t e s t s a id a ls o t o determ ine the i n t e r e s t o f th e stu d e n ts in th e s u b j e c t. E ighteen q u e stio n s were in clu d ed on th e q u e stio n n a ire which could be answered by th e w r itte n resp on se ^YesHo r,,Ho.^ Y arious a u t h o r it ie s s ta te d th a t the s t a t i s t i c a l t r e a t ­ ment of t h is stu d y would have to be somewhat d iffe r e n t from th a t o f o th er sten ograp h ic s tu d ie s as t h i s one had been most­ l y concerned w ith h earin g and would have to be tr e a te d by meth­ ods o f h earin g measurements*

As h e a r in g standards were r e c e iv ­

in g so much a t t e n t io n at th e tim e o f the w r itin g , i t was thought b e st to c a lc u la t e the new p ercen ta g es agreed upon at the Ameri­ can M edical A s s o c ia tio n o f June, 1943. In the meantime, th e w r ite r sen t the in d iv id u a l r e p o r ts o f th e h ea rin g t e s t s to L. A. Watson, P resid en t o f the Maico Company.

Mr. Watson had made s tu d ie s on the im portant speech

fr e q u e n c ie s n e c e ssa r y in th e i n t e l l i g i b i l i t y o f sp eech , and had a ls o w r it te n an e x c e lle n t monograph on the stu d y .

He was

in t e r e s t e d in the stu d y o f h earin g standards fo r sten o g ra p h ers, and he and h i s la b o r a to r y te c h n ic ia n s c o lla b o r a te d . Hie shorthand grades o f a l l th ose tearing th e h earin g t e s t were secured*

These grades rep resen ted a stu d y o f the

su b je c t fo r fift y -m in u te p e r io d s , f i v e p erio d s a week, w ith tw enty weeks in a sem ester*

Each sem ester was d iv id e d in t o

two p erio d s o f 10 weeks each so th a t each stu d en t had r e c e iv e d a grade fo r the f i r s t 10 weeks when the h ea rin g t e s t s were made.

The stu d e n ts were graded on the fo llo w in g b a s is : ”A”

E x c e lle n t , ”B” Good, *0" F a ir , “D” Merely P a ssin g , ”F” F a il ­ u r e , " I n c .” in com p lete because o f absence ra th er than f a i l ­ ure to com plete th e course* by

They were graded on work h a b its

meaning " A ccep ta b le,” and ”H” meaning "Heeds t o Im prove.” Throu^iout the stu d y , lib r a r y research was u se d .

B ib li­

o grap h ies were co n su lted along with th e card ca ta lo g u e s and in ­ d ex es.

Many books and p e r io d ic a ls were read in th e ed u ca tio n a l

and g en era l lib r a r y , but l i t t l e in form ation was found on h ear­ in g standards although th e r e was a great d eal on problems and ca u ses o f f a i l u r e of sten ograp h ic students#

A r t ic le s in current

p u b lic a tio n s in th e s c ie n c e lib r a r y a ffo r d e d v a lu a b le inform a­ tio n .

The b ib lio g r a p h ie s c o n su lte d h ere le d to current p u b li­

c a tio n s in th e m edical lib r a r y from vfeich th e b est in form ation was r e c e iv e d on h earin g and h earin g stan d ard s.

A ll o f th e s e

a r t i c l e s were based on s tu d ie s g ra d u a lly le a d in g to b a s ic in f o r ­ m ation fo r d eterm in in g a standard o f h earin g which th e C ouncil on P h y s ic a l Therapy o f the American M edical A s s o c ia tio n planned to adopt in J u n e ,1 9 4 2 ,due to th e urgent demand fo r one. Even though a u t h o r it ie s s t i l l con sid ered th a t adequate resea rch had not been com pleted on the su b je c t s u f f i c i e n t to

adopt a standard fo r e stim a tin g h earin g l o s s , the demand was so great th a t th e A s s o c ia tio n deemed i t n ece ssa r y t o adopt a p lan o f the committee on th e b a s is of th e e x is t in g research on th e su b ject p r io r to June, 1942.

Dr. Edmund P rin ce Fowler

ex p ressed h is o p in io n in a p e r so n a l l e t t e r of J u ly 9 , 1942, in which he s t a t e d th a t t a b le s had been drawn up conform ing to th e id e a s o f th e m a jo r ity o f th e C on su ltants on Audiometers and Hearing A ids o f the C ouncil on p h y sic a l Therapy of the American M edical A s s o c ia tio n .

Most o f th e c o n te n tio n s o f

the committee c o n s is t in g o f Dr, C. C. Bunch, Dr. Paul S abin e, and Dr. Edmund

P rin ce Fowler were adopted.

However, con sid ­

e r a tio n was not g iv e n in the ad op tion o f th e se ta b le s to "the d iffe r e n c e s o cca sio n ed by nerve d e a fn e ss, and d e s tr u c tiv e d eaf­ n e s s , the changing r a tio n o f l o s s encountered in the d if f e r e n t d egrees o f d ea fn ess and th e d iffe r e n c e s in d ea fn ess between the two e a r s .

Dr, Fowler s t a t e d th a t he con sid ered th a t the

t a b le s were f u l l y "20#* o f f in c a lc u la tio n in many in s t a a e e s . However, q u a n tita tiv e t e s t i n g for determ in in g sim ple h earin g a c u ity o f sc h o o lc h ild r e n had been g e n e r a lly agreed upon and e s ta b lis h e d as was in d ic a te d by th e ad op tion o f the stan d ard , fo r much work had p r e v io u s ly been done alon g t h is l i n e .

FINDINGS AND CONCLUSIONS The lib r a r y re sea rch and p erson al in v e s t ig a t io n by In terv iew and correspondence re p e a ted ly em phasized th a t due to the r e l a t i v e newness o f se v e r a l s c i e n t i f i c in v estig a te, ons in h ea rin g and w ith th e r e c e n t estab lish m en t o f many new th e o r ie s th a t the stu d y was o f tremendous importance from both s o c i a l and v o c a tio n a l p o in ts o f view*

Contrary to the

o p tim is tic hopes o f the w r it e r throughout the stu d y , the con­ c lu s io n was f i n a l l y reached th a t th ere were s t i l l too a a iy q u e stio n s b ein g debated and under in v e s t ig a t io n on h ea rin g and a c o u s tic s to e s t a b l i s h d e f in it e ly a standard of hearing*

B e­

fo r e o t o l o g i s t s a id a c o u s tic a l en g in eers can come to d e c isio n s on stan d ard s, c e r t a in problems r e la t iv e to nerve d e a fn e ss , ob­ s t r u c t iv e d e a fn e ss, r a t io o f l o s s encountered in d iffe r e n t de­ g rees o f d e a fn e s s , and d iffe r e n c e s in d ea fn ess between the two ears w i l l have to be determined*

Although th e C ouncil on

P h y sic a l Therapy of th e American M edical A sso c ia tio n p assed on a standard o f d eterm in in g h earin g a c u ity in June, 1942, th er e were s t i l l many problems whose s o lu t io n s might n e c e s s it a t e a change in the p resen t method o f e stim a tin g h ea rin g l o s s . The new m echanical in v e n tio n s and the new s c i e n t i f i c in te r p r e ta tio n s o f the v ariou s problems o f h earin g are r e la ­ t i v e l y to o new to warrant th e a d v is a b ilit y o f s im ila r in v e s ­ t ig a t io n s on standards a t the p resen t time*

Ihen the ex p er ts

i6 a

agree on the problems th a t have been p o in ted out th a t were arou sin g the in t e r e s t of many during th e stu d y , i t w i l l be tim e enough to b eg in in v e s t ig a t io n on o cc u p a tio n a l stan d ard s. Even though t h e demand fo r standards i s p a r t ic u la r ly imper­ a t iv e fo r o ccu p a tio n s and m ilita r y t r a in in g , c o n c lu sio n s or standards cannot be s e t w ithout th e esta b lish m en t o f c e r ta in s c ie n tific fa c ts .

J u st r e c e n t ly have s c i e n t i s t s been a b le

toj agree on the standard o f h ea rin g , and even some of th e se q u e stio n s have n ot been d e f i n i t e l y d ecid ed .

Due to th e thorough­

n e s s o f t h is in v e s t ig a t io n in which le a d e r s throughout the country were co n ta c ted , th e w r ite r i s co n fid en t th a t the sta n ­ dard su g g ested in the fo llo w in g paragraph was a g reea b le to th e m a jo rity o f le a d e r s in t h i s f i e l d w ith the s ta tu s o f e x i s t in g s c i e n t i f i c in form ation such as i t was when the study was made. In a p erson al communication on June 29, 1942, in which he was in te r p r e tin g th e new ta b le adopted by th e M edical A sso­ c i a t i o n , Mr. I*. A. Watson, who has done co n sid era b le resea rch on th e i n t e l l i g i b i l i t y o f sp eech, e x p r e sse s h i s op in io n r e la ­ t i v e t o t h i s study by sayin g th a t a c h ild would have to have a l o s s o f more than 10 d e c ib e ls b efo r e he would be co n sid ered to have any s i g n i f ic a n t d i s a b i l i t y w h atsoever•

He fu r th e r s ta te d

th a t a c h ild would have t o have a 10 per cent d i s a b i l i t y or p ercen tage o f l o s s r a tin g b efore he would be con sid ered handi­ capped s u f f i c i e n t l y to in t e r f e r e at a l l w ith sten o g ra p h ic or s e c r e t a r ia l work.

166

As to th e r e s a l t s o f the h ea rin g t e s t s o f the groap o f 100 s tu d e n ts , i t was the op in ion o f Mr* Watson and h is la b o ra to ry te c h n ic ia n s th a t th ere were on ly s i x stu d en ts w ith q u e stio n a b le h ea rin g a c u ity con cern in g whom th ere could be any p o s s ib le doubt as to t h e ir h ea rin g a f f e c t in g t h e ir e f f i ­ c ie n c y in the o ccu p ation o f sten ograp h y.

Repeated audiom etrie

t e s t s in con n ection w ith th e thorough o t o lo g ic a l exam inations might tend to in c r e a se pr d ecrea se t h i s number a f t e r the study had been con tin ued over a period o f a t l e a s t one y ea r. Some o f the o t o l o g i s t s co n sid ered th a t th ere were many oth ers o f t h is group who might be co n sid ered handicapped due to h e a r in g .

As a lrea d y p o in te d o u t, a d e f i n i t e d e c is io n could

o n ly be determ ined a f t e r a y e a r ’ s study o f the in d iv id u a ls under c o n s id e r a tio n , and would a ls o be co n d itio n e d accord­ in g to th e type o f th e in d iv id u a l, th e typ e and degree o f impairment as w e ll as i t s p r o g r e ssiv e t e n d e n c ie s , th e type o f employer under whom each would work, th e n o ise and acou s­ t i c a l c o n d itio n s o f the o f f i c e , th e average d is ta n c e which the employee works most o f the time from th e employer or h is co w orkers, whether or not th e in d iv id u a l was r ig h t or l e f t handed which would determ ine th e h earin g a c u ity o f the stenographer a cc o rd in g to th e ear u s u a lly turned towards the speaker.

Much o f the e f f i c i e n c y o f the sten ograp h er a ls o depends on the v o ic e o f the d ic ta to r as to h i s d is t in c t iv e n e s s o f enun­ c ia t io n , th e sten o g ra p h er1s f a m ilia r it y w ith th e s e c t io n a l a c c e n t, the d ic t a t o r ’ s customary mannerisms of d ic t a t io n in d i r e c t ly fa c in g the sten ograp h er so th a t she might even read l i p s in which words or e x p r e ssio n s a ro se w ith which she was un f a m ilia r , or adverse methods of d ic t a t io n which might i n t e r ­ rupt the sound-wave and make h ea rin g and tr a n s c r ip tio n extreme ly d iffic u lt# Thus th e w r ite r a ccep ts the o p in io n o f Mr. Watson and h is te c h n ic ia n s th a t th e r e were on ly s i x o f th ese stu d e n ts With q u estio n a b le h ea rin g a c u it y fo r stenography.

I t i s to

be remembered th a t accord in g to th e former method o f e s tir > m ating p ercen tage l o s s , th a t th e d e c ib e l l o s s i s m u ltip lie d by 0 .8 o r .8 3 and co n seq u en tly a b in a u ra l l o s s of 12 d e c ib e ls i s equal to approxim ately a 10 per cent h earin g l o s s . The q u e stio n n a ire r e v e a le d th a t the stu d e n ts began the stu d y o f shorthand u s u a lly in the e le v e n th grade.

There were

more b©gi*mi&g the shorthand in the second sem ester than in the f i r s t sem ester o f the group of 70 handing in th e q u e stio n ­ n a ir e ,

There were 50 o f t h i s number who in d ic a te d th at th ey

were stu d y in g shorthand because i t gave them an op p ortu n ity to earn a l i v i n g , and th e same number were stu d yin g i t because i t t r a i n e d them fo r an occu p ation which th ey lik e d .

The th ir d

168

most im portant reason fo r ta k in g up th e stu d y as in d ic a te d by th e r e p lie s was because o f the f a c t that the stu d e n ts must or wanted to work when th ey f in is h e d h igh sc h o o l.

P r a c t ic a lly

a l l o f them, th en , were stu d y in g i t from an o ccu p a tio n a l p o in t o f view . The r e p l i e s to th e o th er q u e stio n s a ls o tend ed to sub** s t a n t ia t e th e f a c t th a t th e stu d e n ts were d e f i n i t e l y stu d yin g th e su b je c t due t o v o c a tio n a l c h o ic e , fo r 60. out o f th e 70 were in ten d in g to tak e a com plete commercial cou rse; 66 had taken o th er commercial s u b je c ts ; and 53 planned t o tak e sh o r t­ hand th e fo llo w in g y e a r .

There were 48 who exp ressed t h e ir

in t e n t io n of b ein g h ir e d as a stenographer or se c r e ta r y ; 51 lik e d shorthand b e tte r a t th e end o f th e sem ester than a t the b egin n in g although some in d ic a te d th a t th ey had alw ays lik e d i t and had made an

average; con seq u en tly, th ey would not

n e c e s s a r ily have lik e d the su b je c t any b e t t e r .

There were

f i f t y - f i v e o f th e group who thought th ey would make b e tte r grades on shorthand the fo llo w in g year as th ey understood th e su b je c t b e t t e r than when f i r s t undertaking the stu d y .

Only

e ig h t exp ressed th e w ish th a t th ey had taken a su b je c t d if f e r e n t from th at o f shorthand w h ile o n ly 20 were d isa p p o in ted w ith t h e ir shorthand g ra d es.

A ccording to the most numerous r e ­

sp o n se s, w r itin g sym bols, sp eed , and E n g lish , gave th e se f i r s t y ea r stu d en ts the mas t tr o u b le in b egin n in g shorthand. In co n n ectio n w ith th e r e la t io n o f h ea rin g to shorthand

as in d ic a te d by the q u e stio n n a ir e , the in form ation i s ra th er in s ig n if ic a n t *

Only two thought th a t th ey would have done

b e t t e r i f t h e ir tea ch er had spoken more d i s t i n c t l y ; s i x had d i f f i c u l t y in understanding o th e r s . taken o th er audiom eter t e s t s .

There were 14 who had

Only 7had been to a d octor

be­

cause o f ear tr o u b le , and one thought

th a t her h ea rin g had

h elp ed to low er h er shorthand grade.

Only s i x had exp erien ced

tr o u b le w ith t h e ir ea rs which th e y did not co n sid e r se r io u s enough to see a d o c to r .

A ll o f them had had from one to fou r

communicable d is e a s e s such as s c a r le t fe v e r , m e a sle s, d ip h th e r ia , mumps or whooping cough which might have in d ir e c t ly have a f ­ fe c te d t h e ir h earin g though perhaps not in any o f th e se c a se s stu d ie d . Although two o f th o se who were found to have hear! ng impairments were n ot p lann ing to con tin u e the course th e f o l ­ low in g y ea r, th ey in d ic a te d th a t th ey did not co n sid er th a t t h e ir h ea rin g had a f f e c t e d t h e ir grades and th at they did not w ish th a t th ey had tak en a d iffe r e n t su b je c t from shorthand. Only fo u r with d e f e c t iv e h earin g answered th e q u e stio n n a ir e , but none o f them thought th a t the impairment was n o tic e a b le e it h e r in th e classroom or in t h e i r co n v ersa tio n w ith o th e r s. Even though the stu d e n ts w ith im paired h ea rin g had been se p a r a te ­ l y examined by th e o t o l o g i s t and knew som ething o f t h e ir d e f e c t , th ey did n o t g iv e resp o n ses d if f e r e n t from th o se cf normal

h e a r in g c h ild r e n .

I f t h e y h a d b e e n a t t e m p t i n g t o c o v e r up t h e

d e fe c t in th e ir r esp o n ses, t h e ir under o r d in a r y c o n d it io n s ,

im p a ir m e n t w a s s o s l i g h t

th e d e g r e e of

the

t h e y h a d w o u ld n o t h a v e b e e n n o t i c e a b l e t o

th a t

i m p a i r m e n t s w h ic h

th em o r t o o t h e r s

in t h e ir o r d in a r y c o n v e r s a tio n or in a u d ito r iu m s. A c c o r d i n g t o t h e f o r m e r m e th o d o f e s t i m a t i n g p e r c e n t a g e h e a r in g l o s s ,

th e b in a u r a l

(tw o e a r s )

lo ss

fro m 3 t o 24 d e c i b e l s f o r th e 100 s t u d e n t s . tw o w i t h a l o s s d e c ib e ls,

of 3 d e c ib e ls,

o f^ h e a r in g ranged T h e r e w e re o n l y

and o n l y one w it h o v e r e i g h t e e n

th e e x a c t l o s s b e in g 24 d e c i b e l s .

W ilb e r t F . S n y d e r,

o f t h e N a t i o n a l B u r e a u , a d v i s e d t h e w r i t e r t h a t the m e th o d o f t a k i n g t h e a v e r a g e

usual

d e c ib e l h e a r in g l o s s o f th e sp eech

f r e q u e n c i e s w a s n o t c o n s i d e r e d g o o d p r a c t i c e n o r w a s th e tic e

o f ta k in g th e average l o s s

o f t h e r i g h t an d l e f t

prac­

ears con­

s i d e r e d g o o d p r o c e d u r e a s w as p r e v i o u s l y p o i n t e d o u t i n t h e stu d y .

H ow ever, a s th e b e t t e r m eth od s had n o t b een a g r e e d upon

p r e v io u s to th e

c o m p le tio n o f th e s tu d y , t h e w r it e r u sed th e s e

m eth od s i n d e te r m in in g th e a v e r a g e h e a r in g l o s s e s f o r The b i n a u r a l l o s s r a n g e d a c c o r d i n g l y :

tie

group.

DECIBEL LOSS

PERCENT OF LOO STUDENTS

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

2 8 11 7 14 14 13 9 6 4 5 2 1 0 1 2

24

1

I t w i l l be o b ser v ed t h a t th e p o in t s o f g r e a t e s t f r e ­ q u e n c i e s w e r e a t l o s s e s o f 7 and 8 d e c i b e l s *

T h ere w ere 14

s t u d e n t s h a v i n g l o s s e s o f 7 d e c i b e l s and 1 4 h a v i n g l o s s e s o f 8 d e c ib e ls*

T here w ere 13 h a v in g a l o s s

o f 9 d e c ib e ls.

w i l l a l s o be n o t i c e d t h a t th e ra n g e was a s f o l l o w s : 6 t o 10 d e c i b e l s 5 to 11 d e c i b e l s 4 to 12 d e c ib e ls 3 t o 13 d e c i b e l s A b ov e 1 2 d e c i b e l s

41$ 57$ 74$ 86$ 88$

It

172 Of t h e t o t a l number fr o m t h e tw o s c h o o l s m a k in g a s e ­ m e s t e r a v e r a g e o f G, 60 p e r c e n t o f t h e g r o u p h a d a l o s s

of

7 d e c i b e l s o r b e l o w , 30 p e r c e n t h a d a l o s s o f 8 d e c i b e l s o r b elo w ,

a n d 25 p e r c e n t h a d a l o s s

o f 9 d e c ib e l s o r b e lo w .

.

D e c ib e l

.

.

11

.

C om bined

«D«

7 8 9 1 0 1 1 1 2

63 56 38 19

.

A fter

.

S em ester A verages

L oss o r B e lo w

'

.

.

.

.

P ercen ta g es

91 86 67 52 43 33 . . . .

78 73 55 41 30 16 -

.

th e g r a d e s o f t h i s group w ere s e c u r e d ,

fou n d t h a t th e y ran ged a c c o r d in g ly :

G rades

P e r G ent o f S tu d en ts

A B 0 D F

19 24 20 16 21

*

i t was

130;

DISTRIBUTION OF BEARING LOSSES ACCORDING TO GRADES

D e c ib e l L osses

G rades F

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 T o ta ls

D

0

1 2 4 1 1 4 3 2 2 2 2

1 3 3 2

1 3 4 6 1 2 1

1

T o ta ls B

1 5 3 2 3 2 3 1 1 2 1

A

1 2 4 3 3 2 2 1 1

1 1 1

1

1 21

16

20

24

19

0 0 2 8 11 7 14 14 13 9 6 4 5 2 1 0 1 2 0 0 0 0 0 1 100

Du© t o t h e s e l e c t i o n

o f th e s t u d e n t s ,

se r v e d th a t c o r r e la t io n s are im p o ssib le *

it

w i l l be ob­

T h ere w ere 63 p e r

c e n t o f t h e s t u d e n t s s e l e c t e d w i t h p a s s i n g g r a d e s , o f whom 4 3 p e r c e n t made an a v e r a g e o f

or WB . 11

s t u d i e d t h e i r s t u d e n t s m ore c a r e f u l l y ,

Had t h e t e a c h e r s

t h e r e w o u ld n o t h a v e

b e e n t w i c e a s many m a k in g t h e two h i g h e s t g r a d e s a s w e r e mak­ i n g t h e tw o l o w e s t o r f a i l i n g g r a d e s * fic u lt

Of c o u r s e ,

it

is

d if­

f o r a t e a c h e r t o know much a b o u t h e r p u p i l s w i t h i n a

p e r io d o f 10 or 12 w e e k s, b u t i t

w i l l be o b s e r v e d f r o m t h e

a b o v e t a b l e s t h a t t h e r e w as a d e f i n i t e t e n d e n c y f o r

stu d en ts

h a v i n g p o o r h e a r i n g a c u i t y t o h a v e lo w g r a d e s i n s t e n o g r a p h y as w e ll. I t w i l l be f u r t h e r o b s e r v e d t h a t l o s s e s o f h e a r in g a c u i t y beyond 12 d e c i b e l s i n a group o f g i r l s p ro b a b ly have p r o g r e s s iv e t e n d e n c ie s ,

t h i s a g e w o u ld

and t h o s e a f f e c t e d b e ­

y o n d 1 2 d e c i b e l s s h o u l d b e - t h o r o u g h l y e x a m in e d b y a n o t o l o ­ g i s t i n o r d e r to d e te r m in e t h e c a u s e and n a t u r e o f t h e im p a ir ­ m ent*

I t w o u ld b e n e c e s s a r y t o t a k e s e v e r a l t e s t s on s u c h

c a s e s a s t h o s e and s t u d y th e m f o r i n o r d e r t o w arrant th e

a p e r io d o f a t l e a s t a year

a d v is a b ility

o f t h e i r u n d e r ta k in g

th e s tu d y o f sten ograp h y* It tests

is

f u r t h e r recom m end ed t h a t t h o s e w i s h i n g t o g i v e

I n h e a r i n g t o a g r o u p o f s t u d e n t s who a r e d e s i r o u s o f

b e c o m in g s t e n o g r a p h e r s t h a t t h e y b e g i n g i v i n g s u c h t e s t s a

y e a r p r i o r t o t h a t i n w h ic h t h e s t u d e n t s b e g i n s h o r t h a n d * T h o s e who a r e f o u n d t o h a v e i m p a i r e d h e a r i n g c o u l d b e s t u d ­ i e d d u rin g th e e n su in g i n t e r v a l p r io r to th e b e g in n in g o f th e ir

s tu d y o f s h o r th a n d , and i f

r e p e a te d a u d io m e tr ic t e s t s

r e v e a l e d im p a ir m e n ts w it h i n c r e a s i n g t e n d e n c i e s ,

it

w o u ld

b e b e s t t o a d v i s e t h e s t u d e n t s t h a t t h e i r t i m e w o u ld b e b e t te r sp en t in o th e r f i e l d s o r in r e la te d f i e l d s

i n w h ic h

h e a r in g a c u it y d id not n e e d t o be so keen a s in sten ograp h y* H ad t h e s e s t u d e n t s m a n i f e s t i n g h e a r i n g i m p a i r m e n t s p r e v i o u s ­ ly

s t u d i e d b o o k k e e p in g o r t y p i n g , t h e y m ig h t c o n t in u e i n

t h e s e f i e l d s p e r h a p s w i t h o u t t h e i r h e a r i n g im p a ir m e n t b ecom ­ in g a h a n d ic a p .

I t w o u ld be a w a s t e o f t i m e a n d t r a i n i n g

f o r th e m t o b e a d v i s e d t o d i s c o n t i n u e c l e r i c a l w ork a l t o ­ g eth er*

A lso ,

su c h s t u d e n t s a s t h e s e w o u ld n o t n e c e s s a r i l y

be d is a p p o in t e d i n n o t b e in g a b l e to r e a l i z e t h e i r a m b itio n s* f o r t h e y m ig h t s t i l l

do many f o r m s o f c l e r i c a l

h e a r in g n eed n o t b e so a c u te as in sh o rth a n d .

w ork i n w h i c h The q u e s t i o n

o f t r a n s c r i p t i o n fro m t h e e d ip h o n e o r d ic ta p h o n e h a s b een c o n sid e r e d in t h i s

c o n n e c tio n , and i t

m a ch in es a r e p a r t i c u l a r l y i n j u r i o u s t o

w as f o u n d t h a t tbe s e th o s e h a v in g d e fe c ­

t i v e h e a r in g * It

i s n o t w ise to d is c u s s p la n s w ith a stu d en t con­

c e r n in g h i s

change o f a v o c a t io n u n t i l he h a s ta k e n s e v e r a l

a u d io m e tr ic t e s t s

and th e o t o l o g i s t h a s d e f i n i t e f a c t s a s

176 t o th e n a tu r e o f th e

im p a ir m e n t and t h e p r o b a b l e e f f e c t

of

t h e im p a ir m e n t on t h e f u t u r e e f f i c i e n c y o f t h e s t u d e n t i n h i s v o c a t io n a l c h o ic e * tak e th e s e t e s t s ,

O f t e n s t u d e n t s do n o t know how t o

o r t h e y m ig h t n o t h a v e t h e r i g h t a t t i t u d e ;

t h e i r p s y c h i c r e a c t i o n m ig h t n o t be a s i t t i m e t h e t e s t w as made*

A lso ,

sh o u ld be a t th e

t h e r e m i g h t b e many o t h e r

v a r i a b l e f a c t o r s i n f l u e n c i n g t h e t e s t r e s u l t s t h a t t 1b

one

g i v i n g t h e t e s t m i g h t n o t be t h o r o u g h l y a w a r e o f a t t h e tim e th e t e s t c o ld s,

i s made*

ear ache,

c a b le d i s e a s e s ,

Some o f t h e s e v a r i a b l e f a c t o r s a r e

th roat in f e c t io n ,

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s t u d y a n d on t h e b a s i s o f t h e v a r i o u s i n v e s t i g a t i o n s u n d e r ­ ta k e n , th e w r i t e r ' s c o n c lu s io n i s

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SELECTED BIBLIOGRAPHY I.

R e f e r e n c e s on H e a r in g

A.

3G0KS

B a r t l e t t , M a rio n R a c h a e l , The A u d i t o r y T h r e s h o l d i n R e v e r i e * D o c t o r ’ s d i s s e r t a t i o n , Mew Y o r k : . T e a c h e r s C o l l e g e , C o lu m b ia U n i v e r s i t y , 1 9 3 5 , 42pp* . B o n d , Guy L o r r a i n e , The A u d i t o r y and S p e e c h C h a r a c t e r i s t i c s o f Poor R ea d ers, D octo r’ s d i s s e r t a t i o n . Mew Y o r k : T e a c h e r s C o l l e g e , C o lu m b ia U n i v e r s i t y , 1 9 3 5 ; 4 8 pp* B row n, E; V. L ; , B oth am , L o u i s , and S h am bau gh, G e o r g e , E d i ­ t o r s , 1 9 3 7 Y e a r Book o f t h e E v e . E a r . M ose a n d T h r o a t ; C h ic a g o : T h e Y e a r B ook P u b l i s h e r s * 19 3 7 * 610 p p . Brown, E . Y. L . , B o th a m , L o u i s , C row e, S . J . , E t A l , E d i t o r s , 1 9 5 8 Y e a r Book o f t h e E y e . E a r , M ose a n d T h r o a t ; C h ic a g o : The Y e a r Book P u b l i s h e r s , 1 9 3 8 , 6 0 5 p p . B row n, E; V. L i , B o th a m , L o u i s , C ro w e, S . «T;, E t A l , E d i t o r s , 1 9 5 9 Y e a r Book o f t h e E y e , E a r . M ose and T h r o a t ; C h ic a g o : The Y e a r B ook P u b l i s h e r s , 1 9 3 9 . 635 pp; B o th a m , L o u is * and C row e, S . J ; , E d i t o r s , 1 9 4 0 Y e a r Book o f t h e E y e , E a r , M ose and T h r o a t . C h ic a g o : TEe Y e a r B ook P u b l i s h e r s , 1 9 4 6 , 642 p p • D a v i s , A l f r e d H i , M odern A c o u s t i c s . ' C o m p a n y ,,1 9 3 4 , 5 4 5 pp*

Mew Y o r k :

The M a c m i ll a n

E w in g , I r e n e R ; , and a * W; G . , The H a n d ic a p o f D e a f n e s s . Mew Y o r k : L on g m an s, G r e e n an d Company, 1 9 3 8 ; 327 pp;

E le tc h e r , H arvey, Speech and H eari n g . Mew York: Mostrand Company, 19291 3 3 1 pp; F o w le r , E. P . S r . , M e d ic in e o f th e E a r . N e ls o n and S o n s , 1 9 3 8 ; 369 p p .

Mew Y o r k : ...

D. Van Thomas

F r a m p to n , M e r le E l b e r t , E d u c a t i o n o f t h e H a n d i c a p p e d ; Mew Y ork: Y o n k e r s - Q n - H u d s o n , W o r l d B o o k Company, 1 9 3 8 ; 24 9 p p . G o l d s t e i n , H a r r y , R e a d i n g and L i s t e n i n g C o m p r e h e n s io n ' a t V a r io u s C o n t r o lle d R a t e s . Mew Y o r k : T eachers C o lle g e , C o lu m b ia U n i v e r s i t y , 1 9 4 0 . 69 p p .

179 G o l d s t e i n * M axuA ., The A c o u s t i c M ethod f o r t h e T r a i n i n g o f t h e D e a f and H a rd o f H e a r i n g C h i l d , S t * L o u is; L a r y n g o s c o p e P r e s s , 1 93 9 * 246 pp, . H abbe, S te p h e n , AdJasJm,en,t.§ jft£ A d o l e s c e n t B o y s w i t h I m p a i r e d H e a r i n g s New Y o r k : T eachers C o lle g e , C o lu m b ia U n i v e r s i t y * 8 5 pp* ^ £

L o n g , J o h n A l e x a n d e r , M o to r A b i l i t i e s o f D e a f C h i l d r e n , .Y ork : Colum b i a" U n i v e r s i t y , 1 9 3PT 67 p p .

New

M adden, B i c h a r d , T he S c h o o l S t a t u s o f t h e H ard o f H e a r i n g C h i l d ; An A n a l y s i s o f t h e I n t e l l i g e n c e , tlxe A c h i e v e ­ m en t , and C e r t a i n P e r s o n a l i t y T r a i t s o f t h e H ard o f H e a r i n g C h i l d ;. New Y o r k : T e a c h e r s C o l l e g e , C o lu m b ia U n i v e r s i t y ,' l9 3 1 ± 64 pp* Me L a c h l a n , Norman W i l l i a m , The New A c o u s t i c s ; A S u r v e y o f M odern D e v e lo p m e n t i n A c o u s t i c a l E n g i n e e r i n g * L on don : C x f o r d U n i v e r s i t y P r e s s , Hi M i l f o r d , 1 9 3 6 , 1 6 6 pp* N e u s c h u t z , L o u i s e M , , How t o H e l p Y our H e a r i n g * H a r p e r and B r o t h e r s , 194(5v 179 pp.

New Y o r k :

P e c k , A n n e t t a W e a v er , E a r s a n d t h e Man; S t u d i e s i n S o c i a l ‘Work f o r t h e D e a f e n e d , F T “A* D a v i s Company, 1 9 2 6 ;

217 p p ,

P h i l l i p s , W e n d e l l C . , Y ou r H e a r i n g , How t o P r e s e r v e and A i d It* New Y o r k : D. A p p l e t o n Company, 1 9 3 2 * 2.32 p p . S t e v e n s , S t a n l e y S m i t h , a n d D a v i s , H a l l o w e l l , P s y c h o l o g y and P h y s i o l o g y o f H e a r i n g . New Y o r k : J o h n W i l e y and S o n s , 1938* 489 pp. Ui S . N a t i o n a l I n s t i t u t e o f H e a l t h , P r e l i m i n a r y R e p o r t s o f t h e N a t i o n a l .H e a l t h S u r v e y H e a r ! n g S t u d y S e r i e s ♦ B u l l e t i n I', W a s h in g t o n D. C*, 1 9 3 8 , 25 pp* Waldman, J o h n L , , Wade, F r a n c i s A * , A r e t z , C a r l W ,, H e a r i n g and t h e . S c h o o l C h ild ; H e a r in g , S c h o o l P r o g r e s s .and A ch iev em en t o f P u b li c S c h o o l C h ild r e n . P h ila d e lp h ia W e l l e s , H e n r y H u n t e r , The M e a su r e m e n t o f C e r t a i n A s p e c t s o f P e r s o n a l i t y Among H ard o f H e a r i n g A d u l t s * ftTew Y ork : T e a c h e r s C o l l e g e , C olu m b ia. U n i v e r s i t y , X93 2 . 77 p p .

B*

PERIODICAL ARTICLES

A lm o u r , R a l p h , ”T he B l o c k e d E ar and t h e C a i s s o n W o r k e r ,” L a r y n g o s c o p e , 5 2 :7 5 - 8 1 * , J a n u a r y , 1 9 4 2 * A s h e r t o n , N . , ”The C o c h i e a r N e r v e a n d t h e V a s c u l a r T h e o r y o f N e r v e D e a f n e s s , ” J o u r n a l o f L a r y n g o l o g y and O t o l ­ o g y , 5 5 : 5 3 1 - 5 4 5 , D ece m b e r, 1 9 4 0 i B a b b i t t , Ja m es A *, " P r o g r e s s i v e D e a f n e s s , O t o s c l e r o s i s a n d C lo s e ly R e la te d S u b j e c t s ,” L aryngoscop e, 5 0 :3 8 5 -4 5 1 , May, 1 9 4 0 . B e a s l e y , W i l l i s C , , " C h a r a c t e r i s t i c s and D i s t r i b u t i o n o f ' Im p a ir e d H e a r in g i n th e P o p u la t i o n o f th e U n it e d S t a t e s i J o u r n a l o f th e A c o u s t i c a l S o c i e t y o f A m erica , 1 2 : 1 1 4 - l 2 l 7 “j U l y , " T 9 4 U 7 -------------------------------- ^ --------------------- ’ B e a s l e y , W i l l i s C* « ^C o r r l e a t i o n B e tw e e n H e a r i n g L o s s M e a s u r e ­ m e n t s b y A i r C o n d u c t i o n on E i g h t T o n e s , ” J o u r n a l o f t h e A c o u s t i c a l S o c i e t y o f A m e r ic a , 1 2 : 1 0 4 - 1 1 3 , J u l y , 1940 i B e a s l e y , Y iT illis C . , ”The G e n e r a l P r o b le m c f D e a f n e s s i n t h e P o p u l a t i o n , ” L a r v n g o s c o p e T 5 0 : 8 5 6 - 8 9 9 , S e p te m b e r * 1 9 4 0 * B e r r y , G o rd o n , " A i d s ' t o H e a r i n g , ” R e p r i n t f r o m t h e A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , S e p t e m b e r , 1 9 2 3 . B e r r y , G o r d o n , ”I s A d u l t L i p - R e a d i n g Worth W h i l e ? ” A D e t a i l e d S t u d y o f .1 0 8 C a s e s * R e p r i n t fr o m t h e L a r y n g o s c o p e , S e p t e m b e r 192 2* B e r r y , G o r d o n , ^The P s y c h o l o g y o f P r o g r e s s i v e D e a f n e s s , ” J o u r n a l o f t h e A m e r ic a n M e d i c a l A s s o c i a t i o n , 1 0 1 : 1 5 9 9 - 1 6 0 3 , N o v e m b e r , 193^1 B o r d l e y , J o h n E , , ”T he T r e a tm e n t and P r e v e n t i o n o f D e a f n e s s i n C h i l d r e n , ” S o u th e r n M e d ic a l J o u r n a l , 3 3 : 1 1 8 9 - 1 1 6 4 , N ovem ber, 19401 B u n c h , C* C . , " C o n s e r v a t i o n o f H e a r i n g i n I n d u s t r y , ^ J o u r n a l ° £ t h e -A m e r ic a n M e d i c a l A s s o c i a t i o n , 1 1 8 : 5 8 8 - 5 $ 3 , f e b r u a r y , 1942* B u n c h , C. C . , ”The D e v e lo p m e n t o f th e A u d i o m e t e r , ” L a r y n g o ­ s c o p e , . 5 1 : 1 1 0 0 - 1 1 1 6 , D ecem b erj 1 9 4 1 * B u n ch j C* 0 . , "The D i a g n o s i s o f O c c u p a t i o n a l o r T r a u m a t ic D e a f n e s s : A H i s t o r i c a l and A u d i o m e t r i c S t u d y , ” L a r y n g o s c o p e , 4 7 : 6 1 5 , S ep tem b er, 1937*

181 B u n ch , C. C . , "The R i n n e T e s t a n d t h e A u d i o m e t e r ," A n n a l s o f O t o l o g y , R h i n o l o g y , and L a r y n g o l o g y , 5 0 : 4 7 - 5 4 , M a rch , 1 9 41♦ B u n c h , C. C i , " U s a b le H e a r i n g , " A n n a l s o f O t o l o g y , R h i n o l o g y 4 a n d L a r y n g o l o g y ,. 4 9 ; 5 5 8 - 3 6 ? , J u n e . 1 9 4 0 , C a m p b e ll , Edward H . , and S i l c o x , L o u i s E * * " P r o g r e s s i v e D e a f n e s s — An A b s t r a c t o f t h e A v a i l a b l e L i t e r a t u r e P u b l i s h e d D u r i n g 1 9 4 1 , " L a r y n g o s c o p e . 5 2 : 3 8 0 - 4 1 3 , May, 1942. C a m p b e ll , Edward H . , !fT h e E v a l u a t i o n o f t h e L a b y r i n t h F e n e s ­ t r a t i o n O p e r a t i o n f o r C h r o n ic P r o g r e s s i v e D e a f n e s s , " L a r y n g o s c o p e , 5 1 : 1 0 0 9 - 1 0 5 2 , N o v e m b e r , 19 41* C a n f i e l d , N o r t o n , "The T yp e o f D e a f n e s s Which R e s p o n d s t o F i s t u l i z a t i o n o f th e O t ic C a p s u le ," A n n a ls o f O t o lo g y , R h i n o l o g y , a nd L a r y n g o l o g y . 4 9 : 2 4 8 - 2 6 1 , M arch , 1 9 4 0 . C h a m b e rla in , D o u g la s , " O c c u p a tio n a l D e a f n e s s ; A u d io m e tr ic O b s e r v a t io n s on A u ra l F a t ig u e and R eco v ery * " A r c h iv e s o f O to la r y n g o lo g y , 3 5 :5 9 5 -6 0 2 A p r i l , 1942* C row e, S . J . , "The R e c o g n i t i o n , T r e a t m e n t , a n d P r e v e n t i o n o f H e a r i n g I m p a ir m e n t i n C h i l d r e n , " A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 5 0 : 1 5 - 3 1 , M arcE, 1 9 4 1 . C row e, S . J . , "The R e c o g n i t i o n , T r e a t m e n t , and P r e v e n t i o n o f H e a r i n g I m p a ir m e n t i n C h i l d r e n , " L a r y n g o s c o p e , 5 0 ; 6 5 8 -6 6 2 , J u ly , 1940. . . D a l z i e l , E. D . , and E w in g , A . W. G . , "The P r o t e c t i o n o f H e a r ­ i n g , " J o u r n a l o f L a r y n g o lo g y a n d .O t o lo g y , 5 8 : 2 2 5 - 2 4 2 , J u ly , X 9 4 l. D a v i s , H . , "The C l a r i f i c a t i o n o f C e r t a i n P h a s e s o f t h e P h y s i ­ o l o g y o f H e a r i n g , " L a r y n g o s ^ £ £ , 5 0 : 7 4 7 - 7 5 5 , A u g . , 1 94 0 * D e a n , L. W#, " F i f t y Y e a r s ' o f O t o l o g y i n A m e r i c a , ? A n n a ls o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 5 0 : 1 - 1 4 , M a r c h ,~ T 9 4 1 .

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Camden, New Jersey* F o w l e r , Edmund P r i n c e , "A M ethod f o r M e a s u r i n g t h e P e r c e n t a g e o f C a p a c it y f o r H e a r in g S p e e c h ," J o u r n a l o f t h e A c o u s t ic a l S o c i e t y o f A m e r ic a . 1 3 : 3 7 3 - 3 8 2 , A p r i l , 1 9 4 2 .

182 F o w l e r , Edmund P r i n c e , " H e a r in g S t a n d a r d s f o r A c c e p t a n c e , D i s a b i l i t y R a tin g .a n d D isch a rg e in th e M ilit a r y S e r ­ v i c e s and i n I n d u s t r y ," L a r y n g o s c o p e , 5 1 : 9 5 7 - 9 5 6 , O c to b e r , 1941* F o w l e r , Edmund P r i n c e , "The I l l u s i o n of L o u d n e s s o f T i n n i t u s , I t s E t i o l o g y and T r e a t m e n t j " L a r y n g o s c o p e , 5 2 : 2 7 5 - 2 8 5 , A p r i l , 1942* _ _ F o w l e r , Edmund P r i n c e , " H o n s u r g i c a l T r e a t m e n t f o r D e a f n e s s , " L a r y n g o s c o p e , 5 2 : 2 0 4 - 2 1 7 , M arch, 1 9 4 2 . F o w l e r , Edmund P r i n c e , " T i n n i t u s A urium i n t h e L i g h t o f R e c e n t R e s e a r c h , " A n n a l s o f O t o l o g y , R h i n o l o g y , an d L a r y n g o l o g y , 5 0 : 1 3 9 - 1 5 8 , M a rc h , 1 9 4 1 * F r e y , H u g o , "The P s y c h o l o g i c a l A s p e c t s o f D e a f n e s s , " J o u r n a l o f L a r y n g o l o g y * a n d O t o l o g y . 5 6 : 8 1 - 1 0 0 , M a rc h , 1 9 4 1 . G e i g e r , J* C . , and R o d in , F . H . , and C h a s e , B. A *, "The P r o b ­ le m o f t h e - H a r d o f H e a r i n g S c h o o l C h i l d , " A r c h i v e s o f P e d i a t r i c s , 5 6 :6 0 5 -6 1 0 , S ep tem b er, 1 9 3 9 . G r o v e , W. E . , "An E v a l u a t i o n o f M e n ie r e S y n d r o m e , "A n n a l s o f O t o l o g y , . R h i n o l o g y an d L a r y n g o l o g y , 5 0 : 5 5 - 6 9 , M arch, 1 9 4 1 . G u g g e n h e im , L o u i s K . , " T r e a tm e n t o f D e a f n e s s , " L a r y n g o s c o p e , 5 0 :7 7 3 -7 8 3 , A u gu st, 1940. G u i l d , S* K . , Et* A l * , " I m p a i r e d H e a r i n g i n S c h o o l C h i l d r e n , " L a r y n g o s c o p e , 5 0 : 7 3 1 - 7 4 6 , A u g u s t, 1940* H u g h so n j W a l t e r a n d W i t t i n g , E. G*, " E s t i m a t i o n o f Im p ro v e m en t In H e a r in g F o llo w in g T h erapy o f D e a f n e s s ," A n n a ls o f O t o lo g y , R h in o lo g y a n d L a r y n g o lo g y , 4 9 : 3 6 8 - 5 8 3 , J u n e , 1940 H u g h s o n , W a l t e r , and T h om p son , E v a , " ^ t o l o g i c a l R e s e a r c h and I t s R e c e n t C o n t r ib u t io n s t o C l i n i c a l O t o lo g y ," A n n a ls o f O t o l o g y , R h i n o l o g y , a n d L a r y n g o l o g y . 5 0 : 7 7 - 1 1 2 , M a rch % 1941. H u n t , W e s t l e y M*, "What i s B e i n g Done f o r t h e D e a f n e s s o f S c h o o l C h i l d r e n , " L a r y n g o s c o p e , 5 2 : 2 3 0 - 2 5 1 , M a rch , 194 2 * J o n e s , I s a a c , " Y i t a m i n e s and t h e E y e , E a r , H o s e a n d T h r o a t , " L aryngoscope, 5 0 :5 8 5 -6 3 1 , J u ly , 1940. J o n e s , H . Mao H u g h t o n , " I n j u r i e s o f t h e E a r , " J o u r n a l o f L a r y n g o lo g y and O t o lo g y , 5 6 : 1 8 9 - 2 0 3 , J u n e , 1 9 4 1 .

183 K e r r i d g e , P . M. T * , " D e f e c t s o f H e a r i n g i n C h i l d r e n , " J o u r n a l o f t h e R o y a l I n s t i t u t e o f . P u h l i o H e a l t h an d H y g i e n e . 3 : 3 6 , D ecem ber, 1940* K h u d so n , V. 0 , , "The S e n s i b i l i t y o f t h e E ar t o S m a l l D i f f e r ­ e n c e s o f I n t e n s i t y and F r e q u e n c y , " P h y s i c a l R e v i e w , 2 1 : 8 4 , J a n u a r y , 1940i K o b r a k , F . W ., "Hew T e s t s and C l i n i c a l E x p e r i m e n t s o n H e a r ­ in g ," J o u r n a l. o f L a r y n g o lo g y , 5 5 :4 0 5 -4 2 3 , S ep tem b er, K o b r a k , H* G>, a n d L i n d s a y , J i R*, a n d P e r lm a n , Hi B . , "Ex­ p e r i m e n t a l O b s e r v a t i o n s on t h e Q u e s t i o n ' o f A u d i t o r y F a t ig u e ," L a ry n g o sco p e, 5 1 :7 9 8 -8 1 0 , A u gu st, 1 9 4 1 . L ew y, A l f r e d and L e s h i n , N o r m a n ," F u n c t i o n a l E x a m i n a t i o n o f H e a r in g .? * A r c h i v e s o f O t o l a r y n g o l o g y , 3 5 : 4 3 7 - 4 7 9 , M a rc h , 194^1 L ie r le ,

Dean M ., a n d P a t t e r , J i J i , "The P h y s i o l o g y a n d H i s t o p a t h o l o g y o f t h e M id d l e .Ear,*? A n n a l s o f O t o l o g y , R h i n o l o g y a n d L a r y n g o l o g y j 5 0 : 2 3 6 - 2 7 0 , M arch , 1 9 4 1 .

M a n n in g , A* C*, "The C h i l d H a n d ic a p p e d b y D e a f n e s s , " P a m p h le t o f th e W estern P e n n s y lv a n ia S c h o o l f o r th e D e a f, P it t s b u r g h , P e n n sy lv a n ia i Mao, C. Y . , and H u g h s o n , W ., " P a t e n c y o f t h e E u s t a c h i a n Tube i n R e l a t i o n to P r o fo u n d H e a r in g L o s s i n C h ild h o o d ," A r c h i v e s o f O t o l a r y n g o l o g y , 5 3 :8 2 4 -8 2 9 , May, 1941i M o n tg o m er y , Hi G. , " O p t i c a l Curve A n a l y s i s , " B e l l L a b o r a ­ t o r i e s R e c o r d , 1 8 :2 8 -3 0 * S ep tem b er, 1 9 3 9 , M o r r i s o n , W a l l a c e , "A M odern C o n c e p t i o n o f the* P a t h o l o g y , D i a g n o s i s a n d T r e a tm e n t o f C h r o n ic S u p p u r a t i v e O t i t i s M e d ia ," A n n a l s . o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 5 1 : 1 - 2 1 , M a r c h ," T 9 4 ^ . N e w h a r t , H . , P r e s i d e n t ’ s A d d r e s s , " O b s e r v a t i o n s o n t h e Con­ s e r v a t i o n o f H e a r in g ," L a r y n g o sc o p e , 5 0 :8 4 7 -8 5 5 , S ep tem b er, 194Q . N ew h a rt, H *, " P r o g r e s s i n th e C o n s e r v a tio n o f H e a r in g ," A n n a l s , o f O t o l o g y , R h i n o l o g y and L a r y n g o l o g y , 5 0 : l2 9 -1 3 8 7 ~ M a rch ,1 9 4 X 1 P h o lm a n , A. G . , "The R e a c t i o n s i n t h e E ar t o S o u n d ," A n n a l s o f O t o l o g y , R h i n o l o g y an d L a r y n g o l o g y . 5 0 :5 4 0 - W s , S ep tem b er, 1941 i

184 R o s e n b l i t h , W a l t e r A . , " I n d u s t r i a l N o i s e s and I n d u s t r i a l D e a fn e s s , n J o u r n a l o f th e A c o u sti c a l S o c ie t y o f A m e r ic a , 1 3 : 2 2 0 - 2 2 5 , J a n u a r y , 1942* R o s e n t h a l , M ., "The U s e o f P r o s t i g m i n f o r I m p a i r e d H e a r i n g , " A r c h iv e s o f O to la r y n g o lo g y , 3 4 :5 4 0 -5 7 3 , S ep tem b er, 1 9 4 1 . S a b i n e , P a u l E . * *!0n E s t i m a t i n g t h e P e r c e n t a g e L o s s o f U s e f u l • H e a r i n g , * ! T r a n s a c t i o n s A m e r ic a n Academ y o f O p h t h a l m o l ­ o g y and O t o l a r y n g o l o g y , M a r c h - A p r i l , 1 9 4 2 i S e a l , J . C o le m a n , " P r o s t i g m i n i n O t o l o g y , " The E y e ^ E a r , N o s e and T h r o a t M o n t h l y , 2 0 : 9 - 1 4 , F e b r u a r y , 1 9 4 1 . S e l f r i d g e , G r a n t , " C h r o n ic P r o g r e s s i v e D e a f n e s s w i t h S p e c i a l R e f e r e n c e to E s t r o g e n i c S u b s t a n c e s ," A n n a ls a t O t o lo g y , R h i n o l o g y , a n d L a r y n g o l o g y ," 4 9 : 5 2 - 7 2 , M a rch , 1 9 4 0 . S e l f r i d g e , G r a n t , " E i g h t h N e r v e T on e D e a f n e s s f r o m a N u t r i t i o n ­ a l S t a n d p o i n t , " A n n a l s o f O t o l o g y , R h i n o l o g y and L a r y n g o lo g y , 4 8 : 6 0 8 - 6 3 1 , S ep tem b er, 1 9 3 9 , S e l f r i c i g e , G r a n t , " P r e s e n t S t a t u s o f Y i t a m i n s i n R e l a t i o n 1d. E i g h t h N e r v e and C o n d u c t i o n D e a f n e s s , " A r c h i v e s o f O to la r y n g o lo g y , 3 4 :1 2 5 -1 4 0 , J u ly , 194 1 . Shambau^h* G e o r g e E . , J r . , " C h r o n ic P r o g r e s s i v e D e a f n e s s I n ­ c l u d i n g O t o s c l e r o s i s . a n d D i s e a s e s o f t h e I n n e r E a r ," Ar.chiv,e.s, £ £ O t o l o g y , 2 6 , N o v e m b e r, 1 9 3 7 . S h a m b a u ^ i, G eo rg e E . , and J e n n e s , M in t o n L . , " T h e r a p y o f N e r v e D e a f n e s s a n d T i n n i t u s A u r iu m ," A r c h i v e s o f O t o l a r y n g o l o g y . 3 5 : 5 1 3 - 5 2 2 , A p r i l , 19 42* S o n n e n s c h e i n , R o b e r t a n d L e s h i n , Norm an, " F u n c t i o n a l Exami-rin­ f la t io n o f H e a r i n g ." . A n n a ls o f O t o la r y n g o lo g y , 2 6 : 1 6 4 1 8 4 , N ovem ber, 1 9 3 7 . S p e a k e r , D a v id M . , " E l e c t r o n i c s i n A u d i t o r y R e s e a r c h , " E l e o t r o n i c s . ^1 4 : 3 8 - 4 1 . S e p t e m b e r , 1 9 4 1 ^ S t e i n b e r g , J . C . , and G a r d n e r , Mark R * , " D e p e n d e n c e o f H e a r ­ i n g I m p a ir m e n t o n S o u n d I n t e n s i t y , * ! J o u m a l o f t h e A c o u s t i c a l S o c i e t y o f A m e r i c a . 9 : 1 , July7™19*^7'. S t e i n b e r g , J . C : , " I s Tim e Out o f T une*" B e l l L a b o r a t o r i e s R ecord. 2 :1 5 4 -1 5 7 , J u ly , 1926. S t e i n b e r g , J . C . , a n d G a r d n e r , M. B * , "On t h e A u d i t o r y S i g ­ n i f i c a n c e o f H e a r i n g L o s s , " J o u r n a l o f t h e Ac o u s t i c a l S o c i e t y o f A m e rica . 1 1 : 2 7 0 , J a n u a ry , 1 9 4 0 .

185 S t e i n b e r g , J . C . . M o n tg o m er y , H i C . , a n d G-ardner, M. B . , " R e s u l t s o r t h e v f o r l d f s F a i r s * H e a r i n g T e s t s , *? P a m p h le t f u r n i s h e d t h r o u g h t h e c o u r t e s y o f t h e B e l l T e le p h o n e L a b o r a t o r ie s , S t u h l m a n , 0 . , "The A s y m m e t r i c a l R e s p o n s e o f t h e Human E ar i n R e l a t i o n t o t h e P r o b le m o f C o m b in a t io n T o n e s , " B u l l e t i n o f th e A m e r ic a n M u s i c a l S o c i e t y , 5 : 1 9 - 2 0 , 1 9 4 1 . Thau, W illia m , " P urkyne, A P io n e e r i n P s y c h o lo g y o f S i g h t . and H e a r i n g , " E y e . E a r , N o s e and T h r o a t M o n t h l y , p p i 2 3 7 - 2 4 3 , .S e p t e m b e r , 1 9 4 1 . W a ts o n , L . A . , " A u d i o m e t e r s , H e a r i n g A id s ', and t h e Ear S p e c i a l i s t , " M onograph f u r b i s h e d t h r o u g h t h e c o u r t e s y o f t h e M a ic o Company. W a ts o n , L . A . , "Why a n d How t o C o n d u ct S c h o o l H e a r i n g T e s t s , " P a m p h le t f u r n i s h e d t h r o u g h t h e c o u r t e s y o f t h e M a ic o Co. ? / a t s o n , N. A . , " I d e a l s and S t a n d a r d s f o r A u d i o m e t e r s and H e a r i n g A i d s , " A d d r e s s t o t h e N a t i o n a l W o rk sh o p , June, 1941, W a ts o n , N, A • , a n d K n u d so n , V. 0 . , " S e l e c t i v e A m p l i f i c a t i o n i n H e a r i n g A i d s , " .Ton-rr>Ah m f Hue. A n a u a ti-n a l Sjac.te.t.y m f A m e r ic a , 1 1 : 4 0 6 - 4 1 9 , A p r i l , 1 9 4 0 . W e l l s , W a l t e r A . , "Some P r a c t i c a l C o n s i d e r a t i o n s w i t h R e g a r d t o H e a r in g T e s t s , " A n n a ls / o f O t o lo g y , R h in o lo g y and L a r y n g o lo g y , 4 9 :4 2 7 -4 3 7 , J u n e, 19 4 0 . W e lls,

W a l t e r A . , ?tThe D an ger t o t h e H e a r i n g A p p a r a t u s i n M odern W a r f a r e ," E y e , E a r , N o s e and T h r o a t M o n t h l y , pp. 4 5 -5 0 , F ebruary, 1 9 4 1 .. W aynne, S h i r l e y , W ., " C i t y N o i s e , " J o u r n a l o f t h e A c o u s t i c a l S o c i e t y o f A m e r i c a , 1 3 : 7 4 7 , D e ce m b e r, 1 9 4 0 . _______

" S o c i e t i e s T r a n s a c tio n s ," A r c h iv e s o f O to la r y n g o lo g y , 3 3 :4 9 2 , Jan u a ry -J u n e, 1941. "The P r e s e r v a t i o n o f S e r v i c e a b l e H e a r i n g , " E d i t o r i a l C o n n e c t i c u t S o u t h e r n M e d io a l J o u r n a l , 4 : 7 4 7 , D e c e m b e r , 1940.

II*

M isc e lla n e o u s

K e r s e y , Dr; V i e r l l f l g , " G r e e t i n g s f r o m L o s A n g e l e s C i t y S c h o o ls ; * S e v e n th A nnual C a l i f o r n i a C o n fe r e n c e o f B u s i n e s s Educ a t i o n * , S a c r a m e n t o : C a l i f o r n i a S t a t e D e p a r tm e n t o f E d u c a t io n , B ureau o f E d u c a t io n , B u l l e t i n 1 , 1 9 4 1 ; S i g n o r e l l i , I r e n e , "The E n c o u r a g i n g F a c t s i n t h e S e c r e t a r i a l P r o g r a m ," S e v e n t h A n n u a l C a l i f o r n i a C o n f e r e n c e o f B u s i n e s s . E d u c a t io n , B ureau o f E d u c a tio n , B u l l e t i n 1 , 1941 N i c h o l s , F r e d e r i c k G *, "Comments o n G u id a n c e and C o u n s e l i n g , ” E ig h t h C a l i f o r n i a .C o n fe r e n c e on B u s i n e s s E d u c a t io n , S a c r a m e n t o : Ca l i f o r n i a S t a t e D e p a r t m e n t o f E d u c a t i o n , B u re a u o f E d u c a t i o n , B u l l e t i n . 1 1 , 1 9 4 1 , p . 3 3 ; T u rse, P aul "The S e l e c t i o n o f P u p i l s f o r S t e n o g r a p h i c C o u r s e s , P h i l a d e l p h i a : F o u r te e n th Y earbook o f 1 th e E a s t e r n C o m m e rc ia l T e a c h e r s A s s o c i a t i o n ; 1 9 4 T , pp* 3 0 2 -

31^1

P h i l l i p s , F r a n k C*, " A b i l i t y G r o u p in g As A F a c t o r o f G u id a n c e i n C u r r i c u lu m S e l e c t i o n , " P h i l a d e l p h i a : F o u r t e e n t h Y e a r b o o k o f t h e E a s t e r n C o m m e r c ia l T e a c h e r s A s s o c i a t i o n , T 9 4 T , p,~W>0~ R y a n , C h r i s t o p h e r M*, " Q u a l i f i c a t i o n s f o r J u n i o r C l e r k s , T y p i s t s , and S t e n o g r a p h e r s R e q u i r e d b y t h e New York C i t y O f f i c e M a n a g e r s , ” New Y o r k : E l e v e n t h Y e a r b o o k o f t h e C o m m e r c ia l B u s i n e s s A s s o c i a t i o n o f New Y o r k -a n d V i c i n i t y , 1 9 4 1 , pp; 3 4 - 4 2 ; " A c h ie v e m e n t S t a n d a r d s I n S e l e c t e d S u b j e c t s i n B u s i n e s s E d u c a tio n i n C a l i f o r n i a . J u n io r C o lleg e s* " S acram en to: C a l i f o r n i a S t a t e D e p a r tm e n t o f E d u c a t i o n , B u re a u o f B u s i n e s s E d u c a t i o n , B u l l e t i n 3^, 1 9 4 1 ; U • S* Summary: O c c u p a t i o n a l S t a t i s t i c s , F i f t e e n t h C e n s u s o f t h e U n i t e ’d’ sr a l^ 'r r im s h ih 'g T 'O n ,~ T J . C . , U . S . D e p a r tm e n t o f Com m erce, B u r e a u o f C e n s u s , 1 9 3 0 , t a b l e I I , p , 8 . W anou s, S . J * , " I n T r a n s c r i p t i o n , " B o w l i n g G r e e n , K e n t u c k y : S e v e n th Y earbook o f th e N a t io n a l B u s in e s s T ea ch ers A s s o c i a t i o n , 1 9 4 1 , pp, 316-322* T a f t , M i l d r e d E v e l y n , " P r o b le m s o f A d v a n c e d S h o r t h a n d , " P h i la d e l p h i a : T h ir t e e n t h Y earbook o f th e E a ste r n C o m m e rc ia l T e a c h e r s A s s o c i a t i o n , 1 9 4 0 ; p . 188 *

187 K e n d a l l , M i l d r e n I . , " P r o b le m s o f E le m e n t a r y S h o r t h a n d G r e g g ," P h i l a d e l p h i a ; T h i r t e e n t h Y e a r b o o k o f th e E a s t e r n C o m m e r c ia l T e a c h e r s A s s o c i a t i o n , 1 9 4 0 ,

ppTTW-OT----------------------------------------------------------------Graham, J e s s i e , " I n S h o r t h a n d , " B o w l i n g G r e e n , K e n t u c k y ; S e v e n th Y earbook o f t h e .N a t io n a l B u s in e s s E d u c a tio n A s s o c i a t i o n . 1 9 4 1 , p* 3 1 5 . N i c h o l s , F r e d e r i c k , G . , "Comments on G u id a n c e and C o u n s e l ­ i n g * ” R e p o r t o f the E i g h t h A n n u a l C a l i f o r n i a C o n f e r ­ e n c e on B u s i n e s s E d u c a t i o n ^ S a c r a m e n t o ; C a l i f o r n i a S t a t e D e p a r tm e n t o f B u s i n e s s E d u c a t i o n , B u r e a u o f B u s in e s s E d u c a tio n , 1 9 4 0 , p . 1 6 3 . H a l l e r , R a lp h s W ., f?The L e g i t i m a t e F i e l d o f S t e n o g r a p h y and T y p in g I n New Y ork C i t y H ig h S c h o o l s i " The E l e v e n t h Y e a r b o o k o f t h e C o m m e r c ia l E d u c a t i o n A s s o c i a t i o n o f t h e C i t 7 o f New York an d V i c i n i t y . B u s i n e s s and B u sin e ss E d u c a tio n , 1 9 40 , p . 1 6 3 . Van O rm er, E . B * , a n d W i l l i a m s , C. 0 . , " E le m e n t a r y S t a t i s t i c s f o r S t u d e n t s o f E d u c a t i o n an d P s y c h o l o g y , " Ann A r b o r , M i c h i g a n , Edw ards B r o t h e r s , I n c . , 1 9 4 0 , p . 8 0 i J e n s e n , O l i v e , " B u ild in g T r a n s c r i p t i o n A b i l i t i e s . " W a sh in g to n , D* 0 * ; N a t i o n a l C o m m e rc ia l T e a c h e r s F e d e r a t i o n F i f t h Y e a r b o o k , 1939T P* 286 i B l a n c h a r d , C ly d e I . , " S h o r th a n d S p e e d B u i l d i n g i n T h r e e A c t s , " New Y o r k ; E l e v e n t h Y e a r b o o k o f th e C o m m e rc ia l E d u c a ­ t i o n A s s o c i a t i o n o f t h e C i t y o f New York and. V i c i n i t y ,

I53CT-1941,' p. 142. C a l i f o r n i a S t a t e D e p a r tm e n t o f E d u c a t i o n . " A c h ie v e m e n t S ta n d a r d s i n S e l e c t e d S u b j e c t s i n B u s in e s s E d u c a tio n in C a lif o r n ia J u n io r C o lle g e s " B u l l e t i n 3 , 1 9 4 0 , p . 9 -1 0 . A m e r ic a n M e d i c a l A s s o c i a t i o n , " P r o g r e s s i l g g o r t o f t h e C o n s u l ­ t a n t s on A u d io m ete rs and H e a r in g A id s o f t h e C o u n c il on P h y s i c a l T h e r a p y o f t h e A m e rica n M e d i c a l A s s o c i a t i o n , ” The J o u r n a l o f t h e A m e r ic a n M e d i c a l A s s o c i a t i o n . 1 1 5 : 8 4 5 -8 5 7 , S ep tem b er, 1 9 4 0 . C o u n c il on P h y s i c a l T h era p y , " A ccep ta n ce T e s t s o f H e a r in g A id s ," R e p r i n t e d f r o m t h e J o u r n a l o f th e A m e r ic a n M e d ic a l A s s o c i a t i o n . 115:1633-1634, N o v e m b e r , 1940i

188 K r a n z , F r e d W ., a n d R u d i g e r * C a r l E i , " R e l a t i o n o f t h e A u d io g r a m M e a s u r e m e n t s t o H e a r i n g A id C h a r a c t e r i s t i c s B a s e d o n C o m m e r c ia l E x p e r i e n c e , " R e p r i n t e d f r o m t h e J o u r n a l o f th e A c o u s t i c a l S o c i e t y o f A m erica , 1 5 : 38 3 -3 6 6 , A p r il, 1942. G a r d n e r , W arren EL., " A u d io m e te r T e s t i n g i n Io w a S c h o o l s , " R e p r in t N o. 4 6 1 , V o lt a B u r e a u , D ecem ber, 1 9 3 6 . G a r d n e r , W arren H . , " H e a r in g T e s t s i n 3 7 Io w a S c h o o l S y s t e m s , " R e p r i n t H o. 4 7 9 , V o l t a B u r e a u , D e c e m b e r , 1 9 3 7 . Di M i c h a e l , S a l v a t o r i , " U s i n g I n t e r e s t s a s t h e B a s i s o f V o c a t i o n a l C h o i c e , " V o c a t i o n s , SO :2 7 0 - 2 7 5 , J a n u a r y . 1942. ' F e d e r a l S e c u r i t y A g e n c y , " R e h a b i l i t a t i o n o f t h e D eaf and t h e H a rd o f H e a r i n g . " .M onograph o f t h e II. S . O f f i c e o f E d u c a tio n , F ebruary, 1941, pp. 2 8 -2 9 . N e w b u r g e r , M .; "The R e l a t i v e I m p o r t a n c e o f H o m o g e n e it y a nd D i f f i c u l t y i n t h e D e v e lo p m e n t o f t h e M e n t a l F a t i g u e a t Two D i f f e r e n t L e v e l s o f I n t e l l i g e n c e , " The J o u r n a l of A p p lie d P s y c h o lo g y , 2 6 :8 1 -9 3 , F eb u rary, 1 942. H a s t i n g s , E d g a r G #, a n d H u t s o n , P e r c i v a l , W ., " S t a t e R eg u ­ l a t i o n o f O c c u p a tio n a l A c t i v i t y , " O c c u p a tio n s , 20: 24 7 -2 5 2 , January, 1942. T r a v i s , L ee E dw ard, S p e e c h P a t h o l o g y , A Dynam ic N e u r o l o g i c a l T r e a tm e n t o f Normal S p e e c h and S p e e c h D e v i a t i o n s . New Y ork : D. A p p l e t o n - C e n t u r y Company, 1 9 3 1 . 3 3 1 p p . M c fa r la n , D o u g la s , " U sin g R e s id u a l H e a r in g ," R e p r in t N o. 1 2 4 , R e p r i n t e d fr o m H e a r i n g N e w s , . A m e r ic a n S o c i e t y f o r t i e H ard o f H e a r in g ., W a s h in g t o n D* C . , N o v e m b e r , 1 9 3 9 . U . S . O f f i c e o f E d u c a t i o n , " I n s t r u c t i o n s f o r U se and I n t e r ­ p r e t a t i o n o f M e d ic a l - R e p o r t Form 4 - 3 d , H e a r i n g D i s ­ a b i l i t i e s . " F e d e r a l S e c u r i t y .A g e n c y , V o c a t i o n a l R e ­ h a b i l i t a t i o n D i v i s i o n , W a s h i n g t o n , O c t o b e r , 1 940 * L y n n d e l i e , V i v i a n , " H e a r in g C o n s e r v a t i o n i n a S c h o o l S y s t e m , " R e p r i n t e d f r o m th e V o l t a R e v i e w , J a n u a r y , 1 9 4 0 . P e t e r s , Edwin F . , " G u id a n c e f o r E x c e p t i o n a l C h i l d r e n , " A m e r ic a n A n n a l s o f t h e D e a f , 8 7 : 1 - 7 , J a n u a r y * 1 9 4 2 . A l f a r o , V i c t o r R . , "The C a u s e s o f D e a f n e s s , " R e p r i n t N o , V o lta B u rea u , A u g u st, 1 9 4 0 .

504,

GLOSSARY OF TERMS A bscessed e a r . A b s c e s s e d e a r i s comm only r e f e r r e d t o a s pu~— r u l e n t o t i t i s m e d ia . T h i s c o n d i t i o n i s c a u s e d b y an i n ­ v a s io n o f b a c t e r i a th r o u ^ i t h e E u sta c h ia n tu b e to th e j m id d le e a r f o l l o w i n g su ch i n f e c t i o n s d i s e a s e s a s pn eu­ m o n i a , m e a s l e s , mumps, o r s c a r l e t f e v e r , A freq u en t c o m p l i c a t i o n i s an i n v a s i o n o f t h e m a s t o i d c e l l s c a u s ­ in g m a s t o id it is . When t h e m i d d l e e a r i s s w o l l e n and f i l l e d w i t h p u s , i t i s v e r y e a s y f o r th e c o n d u c t i o n m e c h a n is m ( t h e t i n y b o n e s a c r o s s t h e m i d d l e e a r ) t o b ecom e damaged* A b so lu te p i t c h . A b so lu te p it c h r e f e r s to th e a b i l i t y p o s ­ s e s s e d b y c e r t a i n p e o p l e t o name t h e m u s i c a l p i t c h o f a n o te w ith o u t th e a id o f a sta n d a r d o f r e f e r e n c e . A c tio n -p o te n tia l, An a c t i o n - p o t e n t i a l i s t h e e l e c t r i c p o ­ t e n t i a l g e n e r a t e d b e t w e e n a n a c t i v e and a n i n a c t i v e r e g io n i n a l i v i n g t i s s u e w henever th e n e r v e - f i b e r or th e m u s c l e - f i b e r e le m e n ts at th e t i s s u e i s a c t i ­ v a ted . The m e t a b o l i c p r o c e s s e s o f t h e t i s s u e s u p p l y t h e pow er f o r t h e g e n e r a t i o n at th e a c t i o n - p o t o i t i a l , and th e a c t i o n - p o t e n t i a l b e h a v e s i n an a l l - o r - n o n e fa sh io n . A d v e n titio u s d e a fn e s s . T h o s e who a c q u i r e d e a f n e s s a f t e r 1 h e p a t t e r n s o f sp eed k have b een a c q u ir e d . A ir co n d u ctio n * The n o rm a l p r o c e s s a t h e a r i n g i n w h ic h so u n d w aves e n t e r th e o u t e r ea r and t r a v e l th ro u g h t h e a i r p a s s a g e s o f th e m id d le e a r t o r e a c h th e h e a r in g n e r v e in th e in n e r e a r . A m p lific a tio n , A m p lif ic a t io n i s th e in c r e a s e i n l e v e l , u s u a l l y m easured i n d e c i b e l s , b ro u g h t about by any p a r t or a l l o f t h e a m p l i f y i n g s y s t e m . I t may r e f e r to t h e in c r e a s e f o r a s i n g l e pure t o n e ,.o r fo r a s c o m p le x a c o m b i n a t i o n o f s o u n d s a s s p e e c h . An o v e r ­ a l l a m p lific a t io n i s th e in c r e a s e in i n t e n s i t y l e v e l b ro u g h t about by h e a r in g a i d a s a w h o le i U n if o r m a m p lif ic a t io n i s a m p lif ic a t io n of a l l f r e q u e n c ie s in th e sp e e c h ra n g e e q u a lly . I t i s n o t a m p lific a tio n o f a l l s p e e c h f r e q u e n c i e s t o t h e same l e v e l , b u t a m p l i ­ f i c a t i o n o f e a c h s p e e c h f r e q u e n c y t h e same a m o u n t. A ttr ib u te . A t o n a l a t t r i b u t e i s an a s p e c t o f t h e s a x s a t i o n p r o d u c e d by a t o n a l s t i m u l u s . Each a t t r i b u t e i s de­ f i n e d by a d i f f e r e n t i a l r e a c t i o n t o a t o n e b y a

1 90 l i s t e n e r under a p a r t ic u la r s e t . The f o u r a s ­ p e c t s t h a t can be d i s t i n g u i s h e d i n s t i m u l a t i o n b y p u r e t o n e s a r e p i t c h , l o u d n e s s , v o lu m e , and d e n sity . A u d io g r a m . An a u d io g r a m i s a g r a p h w h ic h e x p r e s s e s h e a r i n g l o s s .a s a fu n c tio n o f freq u en cy. I t rep resen ts a p e r so n * s a c u i t y o f h e a r in g a t a l l f r e q u e n c ie s th ro u g h t h e d i f f e r e n t p i t c h e s , a s m e a s u r e d by t h e a u d i o m e t e r . H e a r i n g l o s s e s a t d i f f e r e n t p i t c h e s a r e p l o t t e d ona s p e c i a l l y d e s i g n e d graph and t h e p o i n t s a r e j o i n e d t o g e t h e r to fo rm th e h e a r in g cu rve* The p r i m a r y r a n g e w h ic h i s m o s t e s s e n t i a l f o r h e a r i n g s p e e c h i s r eg a r d e d a s t h e m ost im p o r ta n t. The s e c o n d a r y r a n g e i s i m p o r t a n t f o r some s p e e c h s o u n d s and t h e t o n e s b e l o w and a b o v e t h e s p e e c h r a n g e . A u d io m eter. The a u d i o m e t e r i s an e l e c t r i c a l i n s t r u m e n t f o r t e s t i n g th e a c u i t y o f h e a r in g * W ith i t t h e t e s t e r may p r o d u c e a t o n e o f any d e s i r e d p i t c h . By v a r y i n g t h e i n t e n s i t y c f t h e t o n e , h e can a s c e r t a i n th e p o in t a t w h ic h t h e c l i e n t can no lo n g e r h e a r th e t o n e . The i n s t r u m e n t i s c a l i b r a t e d t o show t h e d e c i b e l l o s s o f a c u i t y a t t h e p o i n t a t w h ic h t h e t o n e i s n o l o n g e r heard. A verage d e c ib e l l o s s . A c o n v e n i e n t t e r m f o r i n d i c a t i n g th e degree o f h e a r in g l o s s in t h e sp eech r a n g e, a s in d i­ c a t e d by th e c l i e n t * s a u d io g ra m . I t i s c o m p u te d b y a d d in g t h e l o s s e s a t 5 f r e q u e n c i e s .( 2 5 6 , 5 1 2 , 1 0 2 4 , 2 0 4 8 , and 28 9 6 ) and d i v i d i n g t h e t o t a l by 5 . Some o t o l o g i s t s , h o w ev er, add o n ly t h e f i r s t f o u r f r e q u e n ­ c i e s and d i v i d e by 4 . E ith e r i s e s s e n t i a l ly co rr ec t a l t h o u g h t h e r e s u l t s cf: t h e tw o m e t h o d s m ig h t b e s lig h tly d iffe r e n t. ( I t i s m i s l e a d i n g t o s p e a k cf **an a v e r a g e lo ss* * e x c e p t w h ere t h e l o s s a t t h e v a r i o u s f r e q u e n c ie s i s a p p r o x im a te ly e v e n .) A verage p e r c e n ta g e l o s s . T h i s i s a l e s s a c c u r a t e b u t m ore c o m p r e h e n s ib le t e i m fo r " a v e ra g e d e c ib e l lo ss.* * To d e r i v e i t , s t a r t b y c o m p u t in g t h e a v e r a g e d e c i b e l l o s s * T hen m u l t i p l y t h i s f i g u r e b y 0 . 8 3 . The f r a c t i o n , 0 .8 3 i s u sed a s a m u l t i p l i e r i n o r d e r t o r ed u c e th e 120 d e c i b e l s t o p e r c e n ta g e p o i n t s . A3 a l o s s o f 120 d e c ib e ls r ep re sen ts a 100- per cent l o s s , a lo s s of one d e c i b e l r e p r e s e n t s a l o s s o f .8 3 p e r c e n t (100 d i v i d e d by 1 2 0 )* A 3 0 -d e c ib e l lo s s r ep re sen ts a p er­ c e n t a g e l o s s o f 3 0 x 0 . 8 3 , o r 30 x 0^8* T h is v a r ia ­ t i o n i s d u e t o t h e f a c t t h a t n o o n e kn ow s e x a c t l y t h e d e c i b e l e q u i v a l e n t o f a 1 0 0 - p e r c e n t l o s s ; i t may be 1 2 0 d e c i b e l s , o r some f i g u r e b e t w e e n 1 2 0 a n d 130 d e c i b e l s

191 B e l*

The b e l i s t h e c h a n g e i n th e i n t e n s i t y l e v e l o f a so u n d w h ic h r e s u l t s f r o m a t e n f o l d i n c r e a s e i n t h e e n e r g y c a u s in g th e so u n d . O r, i t i s th e u n i t o f a l o g a r i t h m i c s c a l e e x p r e s s i n g t h e r a t i o o f two a m o u n ts o f pow er* The number o f b e l s e x p r e s s i n g t h i s r a t i o i s th e l o g a r i t h m t o t h e b a s e 10 o f t h i s r a tio .

Bone c o n d u c t i o n . Bone c o n d u c t i o n i s t h e p r o c e s s o f h e a r i n g b y w h ic h s o u n d w a v e s p a s s t h r o u g h t h e b o n y s t r u c t u r e o f th e h e a d - m a s t o i d b u l g e , c r a n iu m , o r t e e t h t o t h e c o c h le a * In ta x e -c o n d u c tio n h e a r in g a i d s , th is p r in ­ c i p l e i s u t i l i z e d by im p r e s sin g m ec h a n ica l v ib r a t o r s t o t h e m a s to id bone d i r e c t l y b e h in d t h e e a r ; t h e s e v i b r a t i o n s a r e c a r r i e d through, t h e b o n e s c f t h e h e a d t o t h e i n n e r e a r w h ere t h e y come i n t o c o n t a c t w i t h th e a u d ito r y n e r v e. C a ta rrh a l d e a fn e s s . The c o n d i t i o n o f c a t a r r h a l d e a f n e s s r e ­ s u l t s when t o n s i l l i t i s , s o r e t h r o a t , o r s i n u s t r o u b l e c a u s e s an i n f l a m m a t i o n a n d e v e n t u a l p e r m a n e n t damage t o t h e E u sta ch ia n tu b e ; When t h i s o c c u r s , t h e t u b e can no l o n g e r f u n c t i o n t o m a in ta in a b a la n c e i n a t m o s p h e r i c p r e s s u r e on b o t h s i d e s o f t h e e a r drum. The i n f l a m m a t i o n may e x t e n d t h r o u g h t h e t u b e an d c a u s e s i m i l a r p e r m a n e n t dam age t o t h e m i d d le e a r i t s e l f " . C o c h le a .

The c o c h l e a i s t h e p o r t i o n o f t h e i n n e r e a r c o n t a i n ­ in g th e a u d ito r y n e r v e . I t d e r i v e s i t s name f r o m t h e f a c t th a t i t i s a s p i r a l bony tu b e , sh aped r e se m b lin g a s n a il's sh e ll;

C o n d u ctio n d e a f n e s s . C o n d u c tio n d e a f n e s s r e s u l t s from a d i s ­ e a s e d c o n d i t i o n o f t h e m id d le e a r . As t h e f u n c t i o n o f t h e m i d d l e e a r i s t o c o n d u c t th e s o u n d w a v e s t o t h e i n n e r e a r , the,- c o n d i t i o n i s o f t e n c a l l e d " c o n d u c t i o n d e a fn e ss ." A ls o , a s t h e d is e a s e d c o n d it io n of th e m id d le e a r form s an o b s t r u c t i o n t o th e p a s s a g e o f sou nd w aves from t h e o u t e r t o t h e in n e r e a r , i t i s o f t e n r e f e r r e d to a s " o b s t r u c t i v e d e a f n e s s , o r m id d le e a r d e a f n e s s ;* ^ T h ese^ term s a re i n t e r c h a n g e a b le . C o n g e n ita l d e a f n e s s . C o n g e n i t a l d e a f n e s s i s due t o a c o n g e n ­ i t a l d e f o r m i t y i n t h e m e c h a n is m o f h e a r i n g ; i t i s t h e o n l y t y p e t h a t i s t r u l y an i n h e r i t a b l e c o n d i t i o n . B i o l o g i c a l c o n g e n i t a l d e a f n e s s i s due t o th e i m p e r f e c t em bryo, e i t h e r i n g row th fo r m a t io n o f t h e o t i c c a p ­ s u l e , tem p o ra l b o n e , b r a in o r h i s t o l o g i c a l s t r u c t u r e s a s s o c i a t e d w i t h t h e h e a r i n g m e c h a n is m . P a th o lo g ic c o n g e n it a l d e a fn e ss in c lu d e s tr a n sm issio n o f h e r e d ita r y t e n d e n c i e s t o d e a f n e s s t h r o u g h c o n s a n g u i n i t y i n m a rm ia g e , s y p h i l l i s , t u b e r c u l o s i s , r i c k e t s , i n t r - u t e r i n e

192

hemorrhage, e t c . C y c le * D e a f*

The c y c l e i s o n e c o m p l e t e s e t a p e r io d ic q u a n tity *

of r e c u r r e n t v a lu e s o f

A l l p e r s o n s b o r n w i t h o u t h e a r i n g or t h o s e who h a v e l o s t t h e i r h e a r in g b e fo r e le a r n in g t o t a l k . P erson s i n t h i s group f r e q u e n t l y le a r n to s p e a k , b u t s p e c i a l t r a i n i n g i s r e q u ir e d *

D e c ib e l,

The d e c i b e l i s t h e l e a s t amount cf c h a n g e i n t h e l o u d n e s s o f a s o u n d t h a t c a n b e d e t e c t e d b y the norm al e a r . I t i s on e-ten th of a b e l. The number cf d e c i b e l s d e n o t e s t h e r a t i o o f tw o a m o u n ts cf pow er and i s 10 t i m e s t h e l o g a r i t h m t o t h e b a s e 10 o f t h i s r a t i o . The a b b r e v i a t i o n d b . i s f r e q u e n t l y u s e d f o r the t e r m d e c ib e l. The d e c i b e l i s a l s o r e f e r r e d t o a s a s e n ­ sa tio n u n it.

D e n s ity .

The d e n s i t y i s t h a t a s p e c t o f a u d i t o r y s e n s a t i o n i n t e r m s o f w h ic h s o u n d s may b e o r d e r e d on a s c a l e r u n n in g from " d en se* t o ^ d i f f u s e . " The d e n s i t y i n ­ c r e a s e s when i n c r e a s e d by i n t e n s i t y a s w e l l a s freq u en cy .

D isto r tio n -p o te n tia l. A d i s t o r t i o n - p o t e n t i a l i s th e e l e c t r i c p o t e n t i a l g e n e r a t e d b y th e d e fo rm in g l i v i n g c e l l . By p e r m i t t i n g a i r t o e n t e r or l e a v e t h e m id d le e a r , i t s e r v e s t o e q u a l i z e t h e a ir p r e s s u r e fro m t h e m id d le e a r w i t h t h e a t m o s p h e r i c p r e s s u r e on t h e o u t e r s i d e o f t h e e a r drum* E u sta c h ia n t u b e . The E u s t a c h i a n t u b e i s a t u b e or c a n a l l e a d i n g from t h e t h r o a t t o th e m id d le ea r* By p e r ­ m i t t i n g a i r to e n t e r or l e a v e t h e m id d le e a r , it s e r v e s t o e q u a l i z e th e a i r p r e s s u r e from th e m id d le e a r w i t h t h e a t m o s p h e r i c p r e s s u r e on t h e o u t e r s i d e o f t h e e a r drum . Forced v ib r a tio n . A f o r c e d v i b r a t i o n i s any v i b r a t i o n w h ic h i s i m p o s e d u p o n a s y s t e m b y an e x t e r n a l f o r c e a n d w h o se freq u en cy i s c o n tr o lle d th ereb y. F requency. The num ber o f c y c l e s o c c u r r i n g p e r u n i t o f t im e o r w h ic h w o u ld o c c u r p e r u n i t o f t i m e i f a l l s u b s e ­ q u e n t c y c l e s w e r e i d e n t i c a l w i t h th e c y c l e tin d e r c o n ­ s i d e r a t i o n , i s th e fre q u en cy * The f r e q u e n c y i s t h e r e c ip r o c a l o f th e p e r io d . The u n i t i s t h e c y c l e p e r s e c o n d , s o m e t im e s a b b r e v i a t e d , " c y c l e s " o r " c . p .S V

1 93 H a rm o n ic * A H a rm o n ic i s a com p lem e n t o f a p e r i o d i c wave or q u a n t i t y h a v i n g a f r e q u e n c y w h ic h i s a m u l t i p l e o f th e fu n d am en tal f r e q u e n c y . A c o m p o n e n t w h o se f r e ­ quency i s t w i c e th e fu n d am en tal fr e q u e n c y i s c a l l e d th e s e c o n d h a r m o n ic . H a rd o f h e a r i n g * T h o s e s u f f e r i n g a p a r t i a l or c o m p l e t e l o s s o f h e a r in g a f t e r th e c o m p lete e sta b lish m e n t o f sp e e c h . C o m p le te e s t a b l i s h m e n t c f s p e e c h d o e s n o t o c c u r u n t i l th e c h i ld i s s i x or e ig h t y e a r s o f a g e . I t may a l s o b e d e f i n e d a s rtT h o s e i n whom t h e s e n s e o f h e a r i n g , a lth o u g h d e f e c t i v e , i s f u n c t i o n a l w ith or w ith o u t a h e a r in g a id .* 1 H e a r in g a i d . A d e v ic e th a t a id s in h e a r in g ; i t i s u s u a lly e l e c t r i c a l , c o n s is tin g of th ree p a r ts: A tr a n sm itte r f o r c o l l e c t i n g t h e so u n d w a v e s a n d c o n v e r t i n g th e m i n t o e l e c t r i c a l im p u ls e s , an a m p l i f i e r f o r i n c r e a s i n g t h e i n t e n s i t y o f t h e i m p u l s e s , and a r e c e i v e r w h ic h c o n v e r t s t h e im p u ls e s b a ck i n t o sou nd w a v e s . H e a r in g -lo ss* H e a r i n g - l o s s i s m e a s u r e d b y t h e number o f d e c i ­ b e l s t h a t t h e i n t e n s i t y o f a t o n e m u st be r a i s e d b e y o n d th e norm al t h r e s h o l d v a lu e f o r t h a t t o n e , i n o r d e r t h a t a d e a f e n e d e a r may d e t e c t i t . The p e r c e n t a g e o f h e a r i n g - l o s s a t a g iv e n fr e q u e n c y i s 100 tim e s t h e r a t i o o f th e h e a r i n g - l o s s in d e c i b e l s to t h a t o f th e n o r m a l t h r e s h o l d c f a u d i b i l i t y and f e e l i n g a t t h a t freq u en cy . H y p a u sic* In cu s.

A t e c h n i c a l term f o r th e h a rd o f h e a r in g ,.

One o f t h e t i n y b o n e s f o r m i n g t h e c o n d u c t i o n c h a i n f o r so u n d w a v e s a c r o s s t h e m i d d l e e a r ;

Inner ear d e a fn e ss. L oss o f h e a r in g a s a r e s u l t m ent cf: t h e a u d i t o r y n e r v e .

o f an i m p a i r ­

In te n sity . I n t e n s i t y r e f e r s t o a d im en sio n of a s t im u lu s . I t m e a s u r e s t h e s t r e n g t h o r t h e m a g n i t u d e o f th e s t i m u l a t i n g agen t* In p la n e p r o g r e s s iv e so u n d -w a v es, i n t e n s i t y i s u s u a l l y m e a s u r e d i n t e r m s o f p r e s s u r e cr e n e r g y - f l o w u s u a l l y r e f e r r e d t o a s p o v je r , b u t , w hen­ e v e r t h e pow er i s n o t p r o p o r t i o n a l t o th e sq u a r e o f t h e p r e s s u r e , e n e r g y - f l o w a l o n e s h o u l d be t a k e n a s th e m easure o f i n t e n s i t y * L a b y r in th itis. I n f l a m m a t i o n o f t h e i n t e r n a l e a r , o r the; c o c h l e a , . v e s t i b u l e , and t h e s e m i - c i r c u l a r c a n a l s .

194 L o u d n e ss -le v e l* The l o u d n e s s l e v e l o f a s o u n d i s t h e i n t e n s i t y - l e v e l o f a 100 c y c l e to n e o f e q u a l l o u d n e s s . L o u d n e s s - le v e l i s m easured in d e c ib e ls or p h on s above th e r e f e r e n c e - in t e n s it y * M a sh in g *

M a s h in g i s t h e number o f d e c i b e l s a l i s t e n e r ' s t h r e s h o ld o f a u d i b i l i t y f o r a g iv e n to n e i s r a i s e d by t h e p r e s e n c e o f a n o t h e r so u n d s

M ic r o p h o n ic ; A m icro p h o n ia i s th e e l e c t r i c p o t e n t i a l p ro ­ d u c e d b y a t r a n s d u c e r w h ic h c o n v e r t s v i b r a t o r y p a r t i ­ c le s in to e le c t r ic a l en ergy. The a l t e r n a t i n g p o t e n ­ t i a l o f th e c o c h le a prod u ced in r e s p o n s e t o a stim u ­ l a t i n g sou n d i s a n a u r a l , o r c o c h l e a r m i c r o p h o n i e . M ixed d e a f n e s s . A c o m b i n a t i o n o f m i d d l e - e a r and n e r v e d e a f n e s s . I n t h e s e c a s e s th e d i s e a s e d c o n d i t i o n u s u a l l y s t a r t s i n t h e m i d d l e e a r a n d g r a d u a l l y i n v a d e s the i n n e r e a r , a f f e c t in g i t as w e ll* nerve d e a fn e ss. H e a r i n g im p a ir m e n t r e s u l t i n g fr o m a d i s e a s e d c o n d i t i o n o f t h e a u d i t o r y i s known a s n e r v e d e a f n e s s * B e ca u se o f t h e l o c a t i o n of t h i s n e r v e i n t h e in n e r e a r , t h e c o n d u ctio n i s a l s o c a l l e d in n e r - e a r d e a f n e s s . A lso , s i n c e t h e f u n c t i o n o f the i n n e r e a r i s t o " p e r c e i v e ” , th e a u d it o r y im p u ls e s co n d u cted t o i t th ro u g h th e m i d d l e e a r , th e term , " p e r c e p t i v e d e a f n e s s " i s o f t e n used; H euron.

A n e u r o n i s an e n t i r e n e r v e - c e l l , a x o n , and d e n d r i t e s .

in c lu d in g c e l 1 -b o d y ,

O b str u c tiv e d e a fn e ss; O b str u c tiv e d e a fn e ss i s m id d le ear o r c o n d u c tio n d e a f n e s s .

th e

same a s

O cc u p a tio n a l d e a f n e s s . O c c u p a tio n a l d e a f n e s s r e s u l t s fro m i n j u r y t o the a u d i t o r y n e r v e a s a r e s u l t f r o m w o r k i n g d u rin g lo n g p e r io d s in a v e r y n o i s y p l a c e . O rgan o f C o r t i * The e n d o r g a n o f t h e n e r v e o f h e a r i n g i s O rgan o f G o r t i . O t i t i s m e d ia .

th e

A g e n e r a l term f o r m id d le -e a r d i s e a s e .

O to lo g ist. A p h y s i c i a n who s p e c i a l i z e s i n ear*

d is e a s e s o f th e-

O to sc le r o s is . A s e r i o u s b u t l i t t l e —u n d e r s t o o d d i s e a s e m i d d l e e a r i n w h ic h t h e s t a p e s b e c o m e f i x e d t o c a r t i l a g e s o f th e o v a l w in d o w . T h i s f i x a t i o n or i t y c a u se s c o n d u c tio n d e a f n e s s , b u t in t im e , in

o f th e the r ig id some

maimer n o t u n d erstood , th e c o n d itio n moves in to th e in n er ear and ca u ses d e te r io r a tio n of th e a u d ito ry n e r v e . I t may n ot he com p letely an in h e r ita b le d i s ­ e a s e , hut i t does occur in f a m ilie s in su cceed in g g e n e r a tio n s . Oval window. The oval window i s the th in c a r tila g in o u s p a r t it io n which se r v e s as an opening f o r sound waves from the m iddle ear to th e in n er e a r . P ercep tiv e d e a fn e s s .

See nerve deafn ess*

Phon*

The phon i s th e u n it o f lou d n ess l e v e l . At a freq u en cy o f 100 c y c le s per second, th e lou d n ess leveik in phons of a pure ton e i s n u m erica lly equal to th e in^ t e n s i t y l e v e l in d e c ib e ls as judged by th e l i s t e n e r s ,

P inna.

The pinna i s th e p r o je c tio n p a rt o f th e ear ly in g o u ts id e the head.

Pure tone* A pure ton e i s a sound produced by an in s ta n ­ tan eou s sound p ressu re which i s a sim ple fu n c tio n of tim e. P u ru len t. Something which c o n s is t s of pus or which gener­ a t e s p us. Purulent l a b r i n t h i t i s , P u ru len t l a b r i n t h i t i s occurs when an a b scessed c o n d itio n o f the m iddle ear spreads through the th in c a r t ila g e s o f the o v a l window in to th e in n er e a r . T his i s a s e r io u s c o n d itio n in which com plete l o s s o f h ea rin g i s u s u a lly the f i n a l r e s u l t . R esid u al h e a r in g . R esid u al h earing i s a term used to d e s ig ­ n a te th a t p o r tio n o f normal h earin g c a p a c ity r e ta in e d by hard o f h earin g p e o p le . S e le c t iv e a m p lific a tio n . S e le c t iv e a m p lific a tio n i s am pli­ f i c a t i o n which v a r ie s in amount a t d if f e r e n t speech fr e q u e n c ie s; i t i s c o n tr o lle d v a r ia tio n ra th e r than u n c o n tr o lle d or p a r t i a l ly c o n tr o lle d v a r ia tio n . S en sa tio n l e v e l . The s e n s a tio n le v e l of a g iv en sound i s th e number o f d e c ib e ls th a t th e sound i s above i t s normal th re sh o ld of a u d ib ilit y . S en sa tio n u n i t .

See d e c ib e l.

196

Sound.

Sound i s th e se n sa tio n produced through th e ear by the a lt e r a t io n s of p r e ssu r e , p a r tic le - d is p la c e m e n t, or p a r t i c l e - v e l o c i t y .

Speech range* The frequency range used by th e human v o ic e in ordinary co n v ersa tio n i s c a lle d the speech ran ge. The primary range i s from 256 to 2896, or a cco rd in g to some a u t h o r it ie s , from 256 to 2048* The second­ ary range i s from 128 to 4096. S u p p ressio n . Sup p ression i s the a b i l i t y to so fte n loud sounds and y e t b u ild up f a i n t e r sounds by a m p lific a ­ tio n . Synapse. A synapse i s the con n ection or reg io n o f con tact between two n eu ron s. A n erve-im p u lse p r o g r e ssin g along the axon of one n e r v e - c e ll must c r o ss a synapse b efo r e rea ch in g the d en d rite or c e l l body of th e next n e r v e - e e l l . The tra n sm issio n o f im pulses a cr o ss a synapses i s su b ject to d if f e r e n t law s from th ose gov­ ern in g tra n sm issio n in n e r v e -fib e r s . Thermal n o is e . A therm al n o ise i s an unp itch ed sound. I t may be produced by th e random v ib r a tio n o f the m ole­ c u le s o f the a ir due t o therm al a g it a t io n or by ran­ dom a g it a t io n o f e le c tr o n s in an e l e c t r i c a l conduc­ to r a m p lified and im pressed on a lo u d -sp ea k er . In a therm al n o is e , the spectrum of sound i s con tin uou s and a l l fr e q u e n c ie s are p r e se n t. T hreshold o f a u d i b i l it y . The th re sh o ld of a u d ib ilit y of any s p e c if ie d frequency i s th e minimal v a lu e of soundp ressu re which produces a to n a l se n s a tio n . The p o in t a t which the p ressu re i s measured must be s t a t e d . Threshold o f h ea rin g . The American T e n ta tiv e Standard Acous­ t i c a l Terminology d e fin e s the normal th re sh o ld o f aud­ i b i l i t y as the modal valu e o f the th re sh o ld s o f au di­ b i l i t y - o f a la r g e number o f normal ears o f p erson s in the age group from 18 to 50 y e a r s. For purposes o f r e ­ co rd in g , the th resh o ld o f a u d ib ilit y a t any frequency i s the audiometer s e t t in g corresponding to the lo w est i n t e n s it y at which th e person b ein g t e s t e d in d ic a t e s th a t he h ea rs the tone more than h a lf of th e number o f tim es th a t i t i s given to him. T in n itu s . T in n itu s r e f e r s to head n o is e s such as b u zzin g , h i s s i n g , or c l i c k in g . The two fundamental ty p e s are

1917 v i b r a t o r y and n o n - v i b r a t o r y . The f i r s t i s c h e m i c a l i n o r i g i n due t o a c t u a l v i b r a t i o n * The s e c o n d i s b io c h e m ic a l i n o r i g i n and n o t due t o any a c t u a l v ib r a ­ tio n . The l o u d n e s s o f t i n n i t u s may b e o b j e c t i v e l y e s ­ t i m a t e d b y c o m p a r in g i t t o an a p p l i e d t o n e o r n o i s e o f known l o u d n e s s . Many h a r d o f h e a r i n g p e r s o n s s u f f e r fr o m s u c h n o i s e s . T o x ic l a b y r i n t h i t i s . T o x i c l a b y r i n t h i t i s i s an : in v a s io n o f p o is o n s in t o th e c o c h le a . T h e s e p o i s o n s may come from c h r o n ic c o n d i t i o n s i n th e m id d le e a r , or t h e y may come d i r e c t l y t h r o u g h t h e b l o o d s t r e a m t o t h e a u d i t o r y n e r v e e n d s i n t h e c o c h l e a w i t h o u t c o m in g th r o u g h th e m id d le e a r . The p o i s o n s c a r r i e d t o t h e n e r v e e n d s b y t h e b l o o d s t r e a m may o r i g i n a t e f r o m t o n s i l s , s i n u s e s , t e e t h , or o t h e r s o u r c e s o f i n f e c ­ t i o n i n t h e b o d y : t h e y may come f r o m c e r t a i n d r u g s w h ic h se e m t o h a v e an a f f i n i t y f o r t h e a u d i t o r y n e r v e ; o r t h e y may be i n t h e b l o o d s t r e a m a s a r e s u l t o f a r e c e n t a t t a c k o f an i n f e c t i o u s d i s e a s e s u c h a s p n e u ­ m o n ia o r s c a r l e t f e v e r . Tympannum. T he ty m p a n n u s i s t h e e a r drum . The m e d ic a l term f o r t h e e a r drum i s " ty m p a n ic m e m b r a n e .” V o lu m e .

V olum e i s t h a t a s p e c t o f a u d i t o r y s e n s a t i o n i n t e r m s o f w h ic h s o u n d s may b e o r d e r e d on a s c a l e r u n n i n g f r o m " s m a l l ” t o " l a r g e . ” The v o lu m e o f a t o n e i n ­ c r e a s e s w ith in c r e a s e d fr e q u e n c y . The w ord " v o lu m e ” i s com m only u s e d by r a d i o e n g i n e e r s t o r e f e r t o t h e i n t e n s i t y o f a s o u n d , and s h o u l d n o t be c o n f u s e d w i t h v o lu m e a s d e f i n e d a b o v e .