A comparison between phonetically balanced wordlists and a phonetically balanced nonsense sylable

list in the measurement of speech intelligibility

Item Type text; Thesis-Reproduction (electronic)

Authors Larsen, William Guy, 1930-

Publisher The University of Arizona.

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A COMPARISON BETWEEN PHONETICALLY BALANCED WORD LISTS AND A PHONETICALLY BALANCED NONSENSE SYLLABLE LIST

IN THE MEASUREMENT OF SPEECH INTELLIGIBILITY

, by ; ;, .

W il l iam G. Larsen

A Thesis Submitted to the Faculty o f the

DEPARTMENT OF SPEECH

In P a r t ia l F u l f i l lm e n t o f the Requirements For the Degree o f

MASTER OF ARTS

In the Graduate College

THE UNIVERSITY OF ARIZONA

1961

STATEMENT BY AUTHOR

This thesis has been submitted in p a r t i a l f u l f i l l m e n t of requirements for an advanced degree at The Un ivers i ty o f Arizona and is deposited in The U n ivers i ty L ib ra ry to be made a v a i la b le to borrowers under rules of the L ib ra ry .

B r ie f quotations from th is thesis are a l lowable w i t h ­out special permission, provided tha t accurate acknowledgment of source is made. Requests for permission for extended quo­ta t io n from or reproduction of th is manuscript in whole or in part may be granted by the head o f the major department or the Dean o f the Graduate College when in t h e i r judgment the pro­posed use o f the mater ia l is in the in te res ts o f scholarship. In a l l other instances, however, permission must be obtained from the author.

APPROVAL BY THESIS DIRECTOR

below:This thesis has been approved on the date shown

GENE ENGLAND, Vf\. D. Assistant Professor o f Speech

M L

ACKNOWLEDGMENTS

The wrI t e r wishes to express his g r a t i tu d e to Gene

England, D irec to r o f the U n iv ers i ty o f Arizona Speech and

Hearing C l i n i c , and to Klonda Lynn, Speech Department Head,

fo r t h e i r guidance and encouragement during the w r i t in g of

th is thes is .

The w r i t e r a lso wishes to thank Kenneth Dimmick and

Henry Schmitz for technical advice in the study.

Appreciat ion for t h e i r cooperation in serving as sub­

je c ts for the study Is extended to Vicki B e l l , Jim Larrabee,

Max Huss, Gail J a f f e , Mary Rule, Jacqueline Brown, Gerald

Si W a r , Sandra Focht, Jim Burkhardt, and Tom Economidis.

TABLE OF CONTENTS

Page

LIST OF TABLES v

Chapter

I. INTRODUCTION AND BACKGROUND. . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . 1Background o f the Study. ...................... 2

Psycho Acoustic Laboratory Auditory Tests. . 3Central I n s t i t u t e for the Deaf Auditory

Test W-1 ...................... 3Central I n s t i t u t e for the Deaf Auditory

Test W-22. . . . . . . . . . . . . . . . . 4Test o f Phonemic D i f f e r e n t i a t i o n - The

Rhyme Test . . . . . . . . . . . ................... 5M u lt ip le -C h o ice I n t e l l i g i b i l i t y Tests. . . . 5CNC Word Tests . . . . . . . . . . 6Newspaper Word Test . . . . . . . . . . . . . 7T h re e -D ig i t Test . ....................... . . . . . . . 7In te r ro g a t iv e or D e c la ra t iv e Sentence Test . 7S y l la b le L is t Tests. ....................... 8

I I . STATEMENT OF THE PROBLEM . ................................ 11

Importance o f the Study. . . . . . . . . . . . 11D e f in i t io n o f Terms. . . . . . . ................... » . 12

I I I . PROCEDURE. . . . . . . . . . . . . . . . . . . . 14

Construction o f the T e s ts ...................... 14Select ion o f Subjects. . . . . . . . . . . . . 18Speech Reception Threshold . . . . . . . . . . 19Presentation o f Tests. . . . . . . . . . . . . 20

IV. PRESENTATION OF DATA . . . . . . . . . . . . . . 23

V. SUMMARY AND CONCLUSIONS. . . . . . . . . . . . . 31

Summary. . . . . . . . . . . . . . . . . . . . 31Conclusions. . . . . . . . . . . . . . . . . . 32

APPENDIX: PHONETICALLY BALANCED NONSENSE SYLLABLE TESTS 34

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . 39

iv

L I ST OF TABLES

Table Page

1. The Frequency of Occurrence o f Vowels in W-22Word L is ts . . ....................... . ................................ 15

2. The Frequency o f Occurrence o f Consonants in W-22Word L is ts . . . . . . . . . . . . ................... . . 16

3. Phonet ica l ly Balanced Word Test (PB) andP h onet ica l ly Balanced Nonsense S y l la b le Test(PBNS) Sequence and S ig na l - to -N o is e Ratios . . . 22

4. Ph on et ica l ly Balanced Word (PB) and Phon et ica l lyBalanced Nonsense S y l la b le (PBNS) Test Scores in Percentages o f I n t e l l i g i b i l i t y and S ig n a l - to -Noise Ratios - I n i t i a l Tests. . . . . . . . . 24

5. P h onet ica l ly Balanced Word (PB) and Phon et ica l lyBalanced Nonsense S y l la b le (PBNS) Test Scores in Percentages o f I n t e l l i g i b i l i t y and S ig n a l - to -Noise Ratios - Retests. . . . . ............................ 25

6. Means and Standard Deviations o f I n i t i a l Tests andRetests for Phon et ica l ly Balanced Word (PB) and P hon et ica l ly Balanced Nonsense S y l la b le (PBNS)T e s ts ................................ 26

7. Results o f T Tests for D if ferences Between Meansand F Tests for D if ferences Between Standard Deviations in Comparing Phonetica l ly Balanced Word Tests w ith Phon et ica l ly Balanced Nonsense S y l la b le Tests . . . . . . . . . . . ....................... 28

v

CHAPTER 1

INTRODUCTION AND BACKGROUND

Introduct ion

The transference o f thoughts from one individual to

another by means of speech sounds is a complicated process.

An idea ar ises in the mind of a man, who, w ith the a id of an

inc re d ib le mechanism o f i n t r i c a t e l y designed nerves, muscles,

a r t i c u l a t o r s , and resonators, t ra n s la te s the thought into the

sounds o f speech. These sounds are transm itted through the

a i r , or through various types o f communication systems such

as telephones, magnetic recordings, radio or t e le v is io n , u n t i l

they reach another complicated mechanism, a human ear. The

process of thought t ransference can be ha lted here, however,

unless the sounds make sense to the hearer, unless he compre­

hends t h e i r meaning, unless the speech sounds are i n t e l l i g i b l e

to him.

Communication among men, the interchange o f thoughts

and ideas, is la rg e ly dependent upon man's a b i l i t y to recog­

n ize and comprehend the sounds o f speech. Hearing a 1 one is

not enough; he must understand what he hears i f communication

is to be accomplished. This comprehension o f the meaning o f

speech is re fe r red to as speech i n t e l l i g i b i l i t y .

This i n t e l l i g i b i l i t y as well as a l l o f the other

factors involved in the o r ig in a t io n , the transference , and

1

2

the receiv ing o f speech are o f primary concern in the f ie ld s

of speech and hearing. A person's a b i l i t y to hear and to

understand the sounds o f speech has been a top ic o f much exper­

imentation and research. The c h a r a c te r is t ic s o f the human

hearing mechanism have been studied in i n f i n i t e d e t a i l . Hear­

ing aids have been examined to determine the acoustica l prop­

e r t i e s necessary for adequate reception.

An important phase o f th is experimentation has been

the construct ion o f various tes ts designed to measure a per­

son's a b i l i t y to comprehend the sounds of speech and to evalu­

ate the transmission and receiv ing c h a r a c te r is t ic s o f communi­

cation systems. These tes ts are known as I n t e l l i g i b i l i t y

Tests. The numerical re s u l t obtained by an ind iv idual taking

th is t e s t is defined as his I n t e l l i g i b i l i t y or A r t ic u la t io n

Score. The stimulus m ate r ia ls used have been words, sentences>

and s y l la b le s which have been presented under d iverse condi­

t io n s . A descr ip t ion of some of these tes ts w i l l be presented

as background in form at ion , which w i l l a s s is t the reader in a

c le a re r understanding o f the proposed hypothesis: th a t a te s t

composed of nonsense s y l la b le s could be favorably compared

with a te s t composed o f meaningful words.

Background o f the Study

I n t e l l i g i b i l i t y te s t in g is a r e l a t i v e l y new f i e l d ,

having i ts beginnings in the e a r ly 1900 's. As has been noted,

the stimulus m ate r ia ls used have been e i th e r words or s y l la b le s .

The m a jo r i ty o f the te s ts , however, have used meaningful words

as the s t im u l i . Several tes ts of th is type w i l l be described

in the fo l low ing paragraphs.

Psycho Acoustic Laboratory Auditory T e s ts . These

tes ts were developed at Harvard U n iv e rs i ty and are re fe rred

to as the PAL or Harvard Tests. The stimulus m ater ia l is com­

posed o f tw o -s y l la b le words, such as doorway, f o o t s t o o l , and

a ? rp la ne . PAL Tests No. 9 and No. 12 were recorded at Harvard

and provided for a quick and r e l i a b l e measure o f the threshold

o f i n t e l l i g i b i l i t y and i ts re la te d c l i n i c a l measure, the hear­

ing loss for Speech (7 :3 2 1 ) .

Central i n s t i t u t e fo r the Deaf Auditory Test W - l . This

t e s t was developed at the Central I n s t i t u t e for the Deaf and

was constructed from the words used in PAL Tests No. 9 and

No. 14 (7 :3 2 2 ) . This o r ig in a l group o f e ig h ty - fo u r words was

presented to a group o f s ix l is te n e rs at s ix d i f f e r e n t inten­

s i t y le v e ls . Data were c o l lec ted in terms o f the number of

errors per word for each l i s t e n e r . From these data the judges

rated the words as easy or d i f f i c u l t . An easy word was defined

as one missed no more than once by a l l s ix l is te n e rs ; a d i f f i ­

c u l t word was one missed f i v e or more times by a l l subjects.

Words f a l l i n g into e i th e r o f these extreme categories were

e l im inated . T h i r t y - s i x words were reta ined from the o r ig in a l

e ig h ty - fo u r a f t e r th is analysis was made. Six d i f f e r e n t word

orders o f the same t h i r t y - s i x words were put together to make

up L is t A through F of C. I .D. Auditory Test W-1.

4

Central I n s t i t u t e fo r the Deaf Auditory Test W-22. This

te s t consists o f a vocabulary o f two hundred monosyllabic words

divided into l i s t s o f f i f t y words each. Each l i s t is said to

be p h on et ica l ly balanced. Hirsh (7 :328 ) s ta tes th a t a l i s t is

ph on et ica l ly balanced i f the speech sounds with in the l i s t

occur with the same r e l a t i v e frequency as they do in a rep re ­

s en ta t ive sample o f English speech. The plan for phonetic b a l ­

ance fo r t e s t W-22 was based on the analysis o f spoken English

by French, C a r t e r , and Koenig (5 ) and the ana lys is o f w r i t te n

English by Dewey ( 2 ) . The f i r s t step in s e t t in g up the plan

for phonetic balance was to decide on percentages for the v a r i ­

ous con sonant- vowe1 arrangements in the words. This decision* :

was based on the ana lys is of the s y l l a b le types in the study

by French, C ar te r , and Koenig w ith the fo l low ing m odif ica t ions:

a l l vowel words were omitted, the percentage o f consonant-

vowel-consonant words was increased s l i g h t l y , and the percent­

age o f words contain ing consonant compounds, such as the " t r "

in t rue or the “ i t 11 in f e l t , was increased by 7 .3 per cent.

The f in a l step was to decide on the d is t r ib u t io n o f

the vowels and consonants w i th in each l i s t . The mean o f the

percentages given by Dewey, and by French, C a r te r , and Koenig

fo r the frequency o f occurrence o f each vowel and consonant

was followed c lo s e ly . The sequence o f the words in the o r i g ­

inal four l i s t s was changed a t random times, thus producing

a to ta l o f twenty-four l i s t s which comprise C . I .D . Test W-22.

5

Test o f Phonemic D i f f e r e n t i a t i o n - The Rhyme T e s t . The

Rhyme Test was constructed by Grant Fairbanks at the Speech

Research Laboratory, U n iv ers i ty o f I l l i n o i s . Fairbanks (3)

re fe rs to th is as a completion type te s t . The vocabulary was

drawn from two hundred and f i f t y common monosyllables of the

Thorndike and Lorge 1 is t in g in The Teachers Word Book o f

30,000 Words (1 1 ) . The two hundred and f i f t y stimulus words

were among the nine thousand most f requent ly used words of the

English language. The stimulus words also involved eighteen

consonant phonemes which accounted for approximately 90 per

cent o f a l l consonant occurrences in the English language,

according to the data by French, C a r te r , and Koenig (5 ) ,

The Rhyme Test vocabulary consists o f f i f t y sets o f

f i v e rhyming words each. The f i v e rhyming words w ith in each

set are spel led a l i k e in the rhyming port ion (stem) and d i f f e r

in the i n i t i a l consonant s p e l l in g by a s ing le l e t t e r . The f o l ­

lowing is an example o f one rhyming set: hot, g o t , n o t , p o t ,

l o t . The te s t forms presented to the subject show the f i f t y

stems in order o f st imulus, each preceded by a space in which

he is required to enter one l e t t e r to complete the s p e l l in g

of the word. I t is estimated tha t the ty p ic a l stem o f fe rs

the average adu lt a choice o f e igh t or nine a l t e r n a t i v e s .

■Mult ip le-Choice, i n t e l l i g i b i l i t y T e s ts . J. W. Black o f

Ohio S ta te U n iv e rs i ty is responsible for compiling two forms o f

m u lt ip le -c h o ic e t e s t s . The vocabulary for th is te s t was taken

from Thorndike data (1 1 ) . The f i r s t to the ten-thousandth

6

most f requent ly used words were screened to remove proper

nouns, homonyms (such as bore and boar) , and homographs (such

as bow ( t i e ) and bow ( to bend)) . The remaining words were

recorded and played to a panel o f e igh t to twelve l i s te n e r s ,

in both qu ie t and noisy condit ions. The c r i t e r i a for se le c ­

t ion of words to be used in the m u l t ip le -c h o ic e te s t l i s t s

were: (a ) a word must have f a l l e n w i th in the range 15-85 per

cent i n t e l l i g i b i l i t y in both quiet and noise and (b) a word

must have been responded to erroneously with at leas t three

incorrect words a minimum o f ten times in noise and f i v e times

in quie t (1 :2 1 5 ) . The remaining words were arranged into a

to ta l o f twenty - four m u lt ip le -c h o ic e te s t l i s t s .

The te s t forms for these l i s t s are composed o f sets

of four words. The reader speaks one of the four words in

the set , and the subject marks the word in the set which he

thinks he has heard.

CMC Word T es ts . The consonant, nucleus s y l la b le , con­

sonant t e s t is a r e l a t i v e l y new i n t e l l i g i b i l i t y t e s t , devised

by Use Lehiste and Gordon Peterson a t the Speech Research

Laboratory o f the U n ivers i ty o f Michigan. The term "nucleus

s y l l a b l e , 66 used in the t i t l e o f th is t e s t , simply re fers to

a vowel. The se lec t ion o f words for th is t e s t was also made

from the Thorndike and Lorge data (1 1 ) . A to t a l o f 1,263

monosyllabic words were analyzed and compared w i th the o r ig in a l

PB Word L is t fo r frequency of occurrence o f vowels and conso­

nants, A l l words chosen for th is l i s t met the requirement o f

7

consonant-vowel“consonant construct ion . The complete CMC

Test is composed of ten l i s t s o f f i f t y words each, represent­

ing a se le c t io n o f f i v e hundred words from the o r ig in a l 1,263.

Newspaper Word T e s t . Stimulus words fo r th is te s t

were selected by taking the f i r s t word from every t h i r d l i n e

of a newspaper column (4 :8 5 0 ) . A l l proper names and the f o l ­

lowing f req uent ly used words were excluded: the , o f , and, t o ,

_a, j a . The l i s t s , on the average, contain 46 .3 per cent one-

s y l la b le , 29 per cent two-sy11 ab le , 16.8 per cent three-

s y l la b le , 6 .4 per cent f o u r - s y l l a b le , and 1.5 per cent f i v e -

s y l la b le words, with an average number o f two s y l la b le s per

word.

T h re e -D ig i t T e s t . F le tcher and Steinberg (4:851)

s ta te tha t th is te s t is composed o f numbers: 1, 2, 3, 4, 5,

6, and 8. The numbers are combined a t random into groups o f

three and presented in the manner of an ordinary a r t i c u l a t i o n

t e s t . The d is t ingu ish ing c h a r a c t e r is t i c o f each number is a

vowel sound, and the numbers are in te rp re ted , p r im a r i ly , by

recognizing tha t vowel.

in te r ro g a t iv e or D e c la ra t iv e Sentence T e s t . The sen­

tences used in th is t e s t are l im i te d to those which contain

simple ideas or questions. They are designed to te s t the

observer 's acuteness o f perception ra ther than his i n t e l l i ­

gence (4 :8 4 8 ) . The subjects are asked to rep ly o r a l l y to the

questions which are presented in a normal conversational man­

ner. Due to memory e f f e c t s , a set o f sentences can be used

with the same subjects only a very few times.

8

In a l l o f the previously described t e s t s , meaningful

words were used as the stimulus m a te r ia l . Addit ional tes ts

have been constructed using nonsense s y l la b le s in place o f

words. A descr ip t ion o f three such tests fo l low s .

S y l la b le L is t T es ts . G. A. Campbel1 made use of

s y l la b le s in te s t in g communication systems as e a r ly as 1910

( 4 :8 0 8 ) . These s y l la b le s were o f the nonsense type and,

th e re fo re , had no meaning. The s y l la b le s were constructed

by combining various i n i t i a l consonants with the vowel / i / ,

such as / I i / or / z i / . The consonant a r t i c u l a t i o n score was

used as the measure for th is t e s t . This measure is obtained

by counting the number of consonants correct 1y perceived by

the subjects being tested.

I. B. Crandall a lso devised an i n t e l l i g i b i l i t y te s t

using s y l la b le s as the stimulus m ater ia l (4 :8 0 8 ) . The s y l ­

lables were o f the vowel-consonant and consonant-vowel type.

All o f the common vowels were used and the combinations were

formed in ways which are usual ly found in w r i t t e n speech. The

sounds occurred with the same frequency as they occur in o r d i ­

nary w r i t te n m a te r ia l . The score obtained on th is te s t was

also ca lcu la ted by considering only the number o f consonants

correct 1y perceived.

H. F letcher and J. C. Steinberg (4 :810 ) describe a

standard i n t e l l i g i b i l i t y te s t which makes use o f consonant-

vowel-consonant s y l la b le s .

9y

They considered the In te rna t iona l Phonetic Association

basic alphabet too complex for te s t in g and so they created a

revised s c i e n t i f i c alphabet of f o r t y - e ig h t simple sounds,

twenty-four consonant, nineteen vowels, and f i v e diphthongs.

Using th is alphabet as the basis , they formed twenty-two simple

s y l la b le s o f the consonant-vowel-consonant type.

In order to make th is type o f s y l l a b le , i t is neces­

sary to have an equal number of both vowels and consonants,

where each consonant is used in both the i n i t i a l and the f in a l

p o s it io n . However, some consonants can be used in only one or

the other p o s i t io n . With th is in mind, a l i s t was developed

which used a l l o f the consonants in both i n i t i a l and f in a l

posit ion except Ji, w, and %, which were used only in the f i r s t

po s i t io n , and zh, nq, and St., which were used only in the

1a t t e r .

The te s t in g s y l la b le s were formed by placing the i n i ­

t i a l consonants, vowels, and f in a l consonants each in a sepa­

ra te box. A card was drawn from each to produce a s y l la b le ,

thus forming twenty-two s y l la b le s . This process, repeated

three t imes, produces s i x t y - s i x s y l la b le s in which the i n i t i a l

consonant appears three t im es, each vowel s ix t imes, and the

f in a l consonant three times.

In order to simulate actual speech, the sy l la b le s were

introduced by short introductory phrases, such as: "The f i r s t

group is . . . ” or " I w i l l now say. . . ."

10

This te s t is administered by supplying blank a r t i c u ­

la t io n te s t record sheets to the subjects and ins truc t ing

them to w r i t e the sounds which they heard in the appropr ia te

columns. A s y l l a b le is considered to be in c o rre c t ly observed

i f any one o f the speech sounds which i t contains is mistaken.

The percentage o f the. to ta l number of spoken s y l la b le s which

are c o r re c t ly observed is c a l le d the s y l la b le a r t i c u la t io n .

Further analysis o f resu lts may be obtained by determining the

number o f times ind iv idual sounds are observed c o r re c t ly . The

resu lts are thus expressed as " in d iv id u a l sound a r t i c u l a t i o n . "

The terms "consonant a r t i c u la t i o n " or "vowel a r t i c u la t io n " may

also be used to re fe r to the percentages o f the to ta l number

of spoken consonant or vowel sounds which are correc t 1y

observed.

The foregoing described tes ts i l l u s t r a t e tha t the

measurement of speech i n t e l l i g i b i l i t y can be accomplished by

the use of a v a r ie t y o f te s t in g m ate r ia ls , including e i th e r

words, sentences, or s y l la b le s . An analys is o f these tests

indicates that i t may be possible to construct a nonsense

s y l la b le l i s t which w i l l measure i n t e l l i g i b i l i t y with grea ter

accuracy and r e l i a b i l i t y . Chapter I I w i l l discuss th is

p o s s ib i l i t y .

CHARTER I I

STATEMENT OF THE PROBLEM

The present invest iga t ion is designed to te s t the

hypothesis tha t p h on et ica l ly balanced nonsense s y l l a b le l i s t s

are as r e l i a b l e and v a l id for te s t in g i n t e l l i g i b i l i t y as the

ph on et ica l ly balanced W-22 word l i s t s , when presented to a

group o f sophis t ica ted l is te n e rs . The study a lso seeks to

point out tha t to ta l perception from minimal cues is e l i m i ­

nated when te s t in g w ith these s y l l a b le l i s t s . There is nothing

f a m i l i a r to f a c i l i t a t e the perception as might be the case i f

words were used instead o f nonsense s y l la b le s .

Importance o f the Study

One needs only to ta b u la te the various devices that

are used for t ra n sm it t in g speech to r e a l i z e the importance o f

a q u a n t i ta t iv e method o f ra t ing t h e i r performance. The te s t in g

m ater ia ls used fo r th is measurement were discussed in the

in troductory chapter. The work o f Fletcher and Steinberg

seems e s p e c ia l ly p e r t in e n t to th is study since i t was based

upon nonsense s y l l a b le stimulus m a te r ia l . The te s t ing mate­

r i a l s composed for the present study d i f f e r from those of the

Fletcher and Steinberg l i s t s in th a t they are ph on et ica l ly

balanced and meet the requirements set up for the C .L D . W-22

l i s t s .

„

12

Nonsense s y l la b le s are o f p a r t ic u la r value in te s t in g

for i n t e l l i g i b i l i t y because they have no meaning, and one s y l ­

la b le cannot be recognized more f req uent ly than another simply

because the l i s te n e r is more f a m i l i a r with i t . The perception

of one phoneme in a s y l l a b le does not give a c lue to the other

phonemes in the same s y l la b le . The nonsense s y l l a b le te s t

thus adequately removes expectancy as an aid in id e n t i fy in g

the sounds heard. Emphasis is place on the exact hearing o f

each ind iv idual phoneme, thus increasing the s e n s i t i v i t y o f

the te s t .

D e f in i t io n o f Terms

Phonetica l ly Balanced L i s t . Hirsh (7 :328 ) states

tha t l$a l i s t is p h o n et ica l ly balanced i f the speech sounds

w ith in the l i s t occur w ith the same r e l a t i v e frequency as they

do in a rep resen ta t ive sample o f English s p e e c h . "

Speech I n t e l l i g i b i l i t y . For the purposes o f th is

study, speech i n t e l l i g i b i l i t y is defined as the a b i l i t y to

perceive and comprehend the sounds o f speech.

A r t i c u l a t i o n . A r t ic u la t io n is the percentage of the

to ta l number o f spoken s y l la b le s or words which are correct 1y

perceived and recorded by the subject. This term is synony­

mous with i n t e l l i g i b i l i t y score.

Nonsense S y l l a b l e . Any combination o f consonant-

vowel or consonant-vowel-consonant which does not convey mean­

ing may be c a l le d a nonsense s y l la b le .

13

Phoneme. While a d e f i n i t i v e discussion o f the term

phoneme is not possible or even necessary for th is study, we

can r e fe r to Kantner and West's (8 :1 8 ) statement tha t "perhaps

the term 1 sound fa m i ly ' is the most adequate simple in te rp re ­

ta t io n o f the term phoneme; i t implies a group o f sounds that

are c lose ly re la te d to each other in some way yet by no means

iden t ica l , et The reader can, for purposes o f c la r i t y , th ink

of the phoneme as a "speech sound" in the discussion to fo l low .

Speech Reception Threshold. Newby (10:110) states

tha t a s u b je c t 's speech reception threshold is tha t point

( in t e n s i ty le v e l ) a t which the subject can repeat simple words

or can understand simple connected speech.

The hypothesis under consideration in th is study neces­

s i ta te d construction o f l i s t s o f p h o n et ica l ly balanced non­

sense s y l la b le s . The method o f construction w i l l be discussed

in the fo l lowing chapter.

CHAPTER 11 I

PROCEDURE

The purpose o f th is study was to construct an i n t e l l i ­

g i b i l i t y t e s t , using nonsense s y l la b le s as the stimulus mate­

r i a l , which could be favorably compared w ith C .L D . W-22

Tests la , 2a, 3a, 4a, and lb w ith respect to r e l i a b i l i t y and

v a l i d i t y .

Construction o f the Tests

The f i r s t task in construct ing the nonsense s y l la b le

te s ts was to make a c r i t i c a l analysis o f the exact frequency

o f occurrence o f each phoneme in the selected W-22 word l i s t s .

Each word was f i r s t t ranscr ibed , using in te rn a t io n a l Phonetic

Association symbols. A Pronouncing D ic t ionary o f American

English by Kenyon and Knott (9 ) was used as a source for

checking the accuracy o f the t ra n s c r ip t io n s . The occurrence

of each phoneme was then ca lcu la ted and entered on a ta b le ,

dupl ica t ions o f which are presented in Tables 1 and 2. Cor­

responding nonsense s y l la b le s were formed in the fo l lowing

manner: The f i f t y vowels were f i r s t l i s te d in order of occur­

rence, and the consonants were then placed, in an a r b i t r a r y

manner, before and a f t e r the vowel sounds u n t i l the exact num­

ber had been used. The s y l la b le s were then randomized in

order to have no sequence of vowels (see Appendix). The

14

/15

TABLE 1

THE FREQUENCY OF OCCURRENCE OF VOWELS IN W-22 WORD LISTS

PB la PB 2a PB 3a PB 4a PB lb

A 4 4 4 3 4

I 7 6 8 8 6

e 6 7 6 6 6

ai 3 3 3 3 3

ae 5 5 5 5 5

a 4 4 5 5 4

i 5 5 3 3 5

u 1 3 2 3 2

e i / e 4 3 4 4 4

ou/o 3 3 3 3 3

0 2 2 1 2 2

u 2 0 2 2 2

arr 1 0 1 1 1

3" 1 1 0 0 1

ju 2 4 2 1 2

OI 0 0 1 1 0

Total 50 50 50 50 50

16

TABLE 2

THE FREQUENCY OF OCCURRENCE OF CONSONANTS IN W-22 WORD LISTS

PB la PB 2a PB 3a PB 4a PB lb

t 1 1 11 11 1 1 1 1

n 10 10 10 10 10

r 8 8 9 9 8

s 6 6 7 6 6

d 6 6 6 6 6

1 6 6 6 6 6

m 5 5 5 5 5

k 4 4 4 4 4

6 2 3 3 2 3

w 3 4 3 2 3

z 4 4 3 4 4

f 2 1 2 1 2

j 1 1 1 2 1

h 3 3 3 3 3

V 3 3 2 3 3

b 2 2 2 2 2

P 2 2 1 1 2

17

TABLE 2 (Continued)

PB 4aPB 3aPB 2aPB PB

hw

Total

18

completed l i s t was audited by two judges who had had advanced

t ra in in g in phonetic t ra n s c r ip t io n . Any s y l l a b le which con­

veyed any degree o f meaning to e i th e r o f the judges was w i t h ­

drawn from the 1 Ls_t and another meaningless s y l l a b l e was

used as a replacement. This e n t i r e process was repeated for

each o f the f i v e l i s t s .

In order to prepare them for presenta t io n , the f i v e

l i s t s o f p h on et ica l ly balanced nonsense s y l la b le s , together

with the C . i .D . W-22 l i s t s la , 2a, 3a, 4a, and lb were recorded

on magnetic tape, using a Bel 1 and Howell Model Number 300M

tape recorder equipped with a VU m eter . The order o f sequence

was var ied by recording the l i s t s in two d i f f e r e n t ways. In

the f i r s t sequence the word l i s t s preceded the nonsense s y l ­

la b le l i s t s ; in the second, the nonsense s y l l a b le l i s t s p re ­

ceded the word l i s t s . Since F le tcher (4 :812) found tha t s y l ­

la b le a r t i c u l a t i o n scores were somewhat higher when introduc­

tory sentences were used, the phrases “W rite the word" or

"Write the s y l la b le " preceded each stimulus on the recorded

tapes.

Select ion o f Subjects

The c r i t e r i a for the se lec t ion of subjects were:

(a) the subject must have had a pure tone threshold of 0 db.

in each ear for a l l frequencies from 128 c .p .s . to 8000 c . p . s . ,

(b) the subject must have had a speech reception threshold in

each ear o f 0 to 10 d b . , and (c ) the subject must have demon­

s tra ted p ro f ic iency in accurate ly t ra n sc r ib in g nonsense s y l ­

lables into phonetic symbols.

19

Pure tone thresholds were obtained by standard audio­

m etr ic procedures as o u t l in ed by Newby (1 0 :7 2 -8 0 ) , using a

Model MA 28 Maico audiometer. These audiometric examinations

were conducted in a soundproof room with ambient noise level

of 35 db.

Speech Reception Threshold

To determine,Speech Reception Threshold, the subjects

were f i t t e d with Permoflux Model MA 28 earphones and placed

in a soundproof room with ambient noise level o f 35 db. The

s t im u l i for Speech Reception Thresholds were presented by l i v e

voice and were composed o f spondees o f Auditory L is t W-1. The

in te n s i ty was regulated by a set o f a t tenuators which made

possible a t tenua t ion over a range o f 110 db. , in one db. steps.

The sensation level a t which the subject was able to repeat

f i f t y per cent of the words was reg is te red as his Speech

Reception Threshold.

The subjects ' a b i l i t y to use phonetic symbols was

ascerta ined by req u ir ing them to t ra n scr ib e a short l i s t o f

nonsense s y l la b le s which were presented o r a l l y . No subject

was chosen who missed more than two o f the tw e n ty - f iv e pre­

sented s y l la b le s . This te s t in g procedure conveniently served

as a t ra in in g period fo r the t ra n s c r ip t io n o f nonsense s y l ­

la b le s .

Ten subjects were se lected , f i v e male and f i v e female,

ranging in ages from twenty to tw e n ty - f iv e years. Each o f the

subjects had had a minimum o f one course o f phonetics at the

co l lege le v e l .

20

Presentation o f Tests

The f in a l experimental te s t in g procedures were con­

ducted by placing the subjects, in d iv id u a l ly , in a soundproof

room and f i t t i n g them with earphones. Each subject was then

instructed to w r i t e the words o f the W-22 1 is ts and to t r a n ­

scr ibe the s y l la b le s o f the nonsense s y l l a b le l i s t s into pho­

n e t ic symbols. The word l i s t s and the s y l l a b le l i s t s were

presented separa te ly . Subjects were instructed to guess a t

the sounds even though the s y l l a b le was not e n t i r e l y c lear to

them. For the purpose of th is study, the guessing was espe­

c i a l l y p e r t in e n t in the perception of the nonsense s y l la b le s .

The stimulus m ater ia l was presented through a console

u n it composed o f a Vi king Model 75 Tape Playback, a two channel

Hewlett Packard 350A a t tenuator system, a two channel VU m eter ,

a Grason S tadler Model 456A noise generator , and two Bogen

Model LOM a m p l i f ie r s .

The in te n s i ty level for speech was a r b i t r a r i l y set a t

60 db. The in te n s i ty o f the w hite noise was a r b i t r a r i l y set

at f i v e d i f f e r e n t le v e ls : 42db., 54 d b . , 60 d b . , 66 d b . ,

and 72 db.

The speech was fed through one channel, w h i le the

noise was fed, simultaneously , through another. In te n s i t ie s

were c o n tro l le d by the two sets o f a t tenuators and VU meters.

Each word l i s t , together w ith i ts corresponding nonsense s y l ­

la b le l i s t , was presented a t a d i f f e r e n t s ig n a l - to -n o is e r a t i o .

21

Each subject heard a to ta l of. f i v e word l i s t s and

f i v e nonsense s y l l a b le l i s t s a t the f i v e d i f f e r e n t s ig n a l - t o -

noise r a t io s , as charted on Table 3.

A re te s t s i tu a t io n was set up to insure r e l i a b i l i t y

o f t e s t re s u l ts . The same ten subjects heard the same ten

l i s t s under the same circumstances, a t the same s ig n a l - t o -

noise r a t io s , w i th in f o r t y - e ig h t hours a f t e r the i n i t i a l te s ts .

The preceding paragraphs have described the procedures

followed in construction and in presentat ion o f the te s t mate­

r i a l . The experimental t e s t re s u l ts and the s t a t i s t i c a l pro­

cedures followed in the analysis o f the data w i l l be presented

in Chapter IV.

22

TABLE 3

PHONETICALLY BALANCED WORD TEST (PB) AND PHONETICALLY BALANCED NONSENSE SYLLABLE TEST (PBNS) SEQUENCE

AND S IGNAL-T O-NOISE RATIOS

Subj ect T estIn te n s i ty Levels

Speech No i se S/N Rat io

Subjects 1, 3, 5, 7, 9 PBNS la 60 42 + 18

PB la 60 42 + 18

PBNS 2a 60 54 + 6

PB 2a 60 54 + 6

PBNS 3a 60 60 0

PB 3a 60 60 0

PBNS 4a 60 66 6

PB 4a 60 66 6

PBNS lb 60 72 - 12

PB lb 60 72 - 12

Subjects 2, 4, 6, 8, 10 PB la 60 42 + 18

PBNS la 60 42 + 18

PB 2a 60 54 + 6

PBNS 2a 60 54 + 6

PB 3a 60 60 0

PBNS 3a 60 60 0

PB 4a 60 66 6

PBNS 4a 60 66 6

PB lb 60 72 - 12

PBNS lb 60 72 - 12

CHAPTER IV

PRESENTATION OF DATA

This study is designed to t e s t the v a l i d i t y and r e l i ­

a b i l i t y o f a ph on e t ica l ly balanced nonsense s y l l a b le te s t

which can be used for te s t ing speech i n t e l l i g i b i l i t y . In

order to t e s t v a l i d i t y , a s t a t i s t i c a l comparison was made

between the a r t i c u l a t i o n scores obtained on the ph on et ica l ly

balanced nonsense s y l l a b le te s ts and the widely used phoneti­

c a l l y balanced word te s ts . To te s t r e l i a b i l i t y , each te s t was

given to each subject a second time under id en t ic a l condit ions.

Tables 4 and 5 show the a r t i c u l a t i o n scores for the

i n i t i a l tests and for the re te s ts . The a r t i c u l a t i o n scores

for the p h o n et ica l ly balanced word tes ts ranged from one

hundred per cent to s ix per cent on the i n i t i a l te s ts , and

from one hundred to fourteen per cent on the re te s ts . The

range o f a r t i c u la t io n scores for the p h on et ica l ly balanced

nonsense s y l l a b le tes ts was from seventy-e ight per cent to

zero per cent on the o r ig in a l t e s t , and from seventy-four per

cent to two per cent on the second te s t .

The means and standard deviat ions obtained from the

above scores are shown in Table 6. In order to determine

whether or not there was a s ig n i f i c a n t d i f fe re n c e between the

mean scores on the p h on et ica l ly balanced word te s ts and the

23

24

TABLE 4

PHONETICALLY BALANCED WORD (PB) AND PHONETICALLY BALANCED NONSENSE SYLLABLE (PBNS) TEST SCORES IN PERCENTAGES

OF INTELLIGIBILITY AND SIGNAL-TO-NOISE RATIOS -INITIAL TESTS

Test S/N Ratio 1 2 3 4Subj ect

5 6 7 8 9 10

PB la + 18 100 92 100 94 94 92 94 96 96 94

PB 2a + 6 90 82 98 74 68 78 82 82 82 78

PB 3a 0 96 74 98 64 68 78 84 68 92 74

PB 4a - 6 34 40 48 36 40 62 56 46 54 62

PB lb - 12 6 10 24 6 20 26 30 20 42 26

PBNS la + 18 66 64 58 64 74 72 78 66 66 62

PBNS 2a + 6 52 50 72 58 56 48 64 50 52 46

PBNS 3a 0 52 40 64 44 48 54 44 52 58 44

PBNS 4a - 6 14 20 18 18 20 26 30 22 32 24

PBNS lb - 12 4 4 6 4 6 2 10 0 10 8

25

TABLE 5

PHONETICALLY BALANCED WORD (PB) AND PHONETICALLY BALANCED NONSENSE SYLLABLE (PBNS) TEST SCORES IN PERCENTAGES

OF INTELLIGIBILITY AND SIGNAL-TO-NOISE RATIOS -RETESTS

T est S/N Ratio 1 2 3

Subj ect

4 5 6 7 8 9 10

PB la + 18 96 98 100 92 94 92 92 98 100 96

PB 2a + 6 92 86 88 84 82 80 66 90 84 84

PB 3a 0 86 80 78 68 68 70 62 86 76 76

PB 4a 6 54 44 50 42 48 56 34 52 40 50

PB lb - 12 20 24 36 22 16 18 16 14 28 22

PBNS la + 18 68 66 60 56 74 72 68 72 72 64

PBNS 2a + 6 56 60 58 56 60 50 56 52 58 34

PBNS 3a 0 52 44 48 52 46 58 48 60 56 42

PBNS 4a 6 28 18 32 10 18 28 16 24 30 24

PBNS lb - 12 12 18 6 8 6 6 2 2 10 6

26

TABLE 6

MEANS AND STANDARD DEVIATIONS OF INITIAL TESTS AND RETESTS FOR PHONETICALLY BALANCED WORD (PB) AND PHONETICALLY

BALANCED NONSENSE SYLLABLE (PBNS) TESTS

Means Standard Deviations

I n i t i a l Test Retest I n i t i a l Test Retest

PB la 95.2 95.8 2.87 3.19

PB 2a 8 1 .4 83 .6 8 .22 7.15

PB 3a 79.6 75.0 12.29 7.96

PB 4a 47.8 47.0 10.34 6.88

PB lb 21.0 21.6 11.31 6.58

PBNS la 67.0 67.2 5.98 4 .90

PBNS 2a 54.8 54.0 8.01 7.71

PBNS 3a 50.0 50.6 7 .50 6.02

PBNS 4a 22.4 22.8 5.63 7.07

PBNS lb 5 .4 7 .6 3.27 5.83

27

corresponding p h o n et ica l ly balanced nonsense s y l l a b le t e s t s ,

the T te s t was app l ied . The formula used for th is c a lc u la ­

t io n , as presented by Underwood (1 2 :1 2 7 ) , is as fol lows:

The F te s t was used to determine whether there was a s i g n i f i ­

cant d i f fe re n c e between the standard deviat ions o f the two

te s ts . The fol lowing formula used fo r the F te s t was pre­

sented by G arre t t ( 4 :3 0 3 ) .

Results of the T and F tests are shown in Table 7.

The T te s t res u l ts show that there is a s ig n i f ic a n t

d i f fe re n c e , above the ten per cent confidence le v e l , between

the mean of each of the p h o n et ica l ly balanced word tests and

the mean o f each corresponding phon et ica l ly balanced nonsense

s y l la b le t e s t , with the exception o f ph on et ica l ly balanced

word te s t lb and p h o n et ica l ly balanced nonsense s y l la b le te s t

lb . Results o f the F te s t show tha t in the i n i t i a l te s t in g

there was a s ig n i f i c a n t d i f fe re n c e between the standard d e v i ­

at ions on three o f the matched sets o f te s ts . Phonet ica l ly

balanced word tes ts la and 4a and t h e i r corresponding phonet i ­

c a l ly balanced nonsense s y l la b le te s ts showed a s ig n i f ic a n t

d i f fe re n c e at the f i v e per cent confidence le v e l . P honet ica l ly

balanced word te s t lb and i ts corresponding phon et ica l ly

OTJiff

28

TABLE 7

RESULTS OF T TESTS FOR DIFFERENCES BETWEEN MEANS AND F TESTS FOR DIFFERENCES BETWEEN STANDARD DEVIATIONS IN COMPARING

PHONETICALLY BALANCED WORD TESTS WITH PHONETICALLY BALANCED NONSENSE SYLLABLE TESTS

T Test^ F Test%

I n i t i a l T est Retest

I n i t i a lTest Retest

PB la - vs - PBNS la 4 .26 4.90 4 .35 2.35

PB 2a - vs - PBNS 2a 2.31 2.82 1.04 1.16

PB 3a - vs - PBNS 3a 2.05 2.44 2.68 1.74

PB 4a - vs - PBNS 4a 2. 16 2.45 3.37 1.05

PB lb - vs - PBNS lb 1.32 1.59 11.95 1.27

1. A T value as high as 3 .25 indicates the 1% level o f confidence; 1.83 indicates the 10% le v e l .

2. An F value as high as 5.35 indicates the 1% level of confidence; 3 .18 indicates the 5% le v e l .

29

balanced nonsense s y l la b le te s t showed a d i f fe re n c e at the

one per cent confidence le v e l . No s ig n i f i c a n t d i f fe re n c e

between the standard devia t ions were found for the retests

at any 1e v e l .

G arre t t suggests that a t e s t - r e t e s t procedure be used

for computing the r e l i a b i l i t y o f a t e s t (6 :3 3 7 ) . The t e s t -

re te s t procedures used in the present study made i t possible

to obtain a measure of r e l i a b i l i t y o f each type o f te s t under

considerat ion. The Pearson product moment c o e f f ic ie n t of cor­

r e la t io n was ca lcu la ted for i n i t i a l t e s t and re te s t o f both

the ph on et ica l ly balanced word te s ts and the p h o n et ica l ly b a l ­

anced nonsense s y l la b le te s ts . The formula used for th is com­

putat ion , as presented by G a rre t t (6 :1 2 6 ) , is as fol lows:

r _ s f e ~N

C o rre la t io n for the p h o n et ica l ly balanced word te s t

and re te s t was 99 .2 , wh i le c o r re la t io n for the phonet ica l ly

balanced nonsense s y l la b le te s t and re te s t was 97 .8 .

The W-22 ph on e t ic a l ly balanced word l i s t te s t has been

previously accepted as a v a l id tool for i n t e l l i g i b i l i t y t e s t ­

ing; th e re fo re , the v a l i d i t y o f the newly constructed phonet i ­

c a l l y balanced nonsense s y l la b le tes t was determined by com­

puting the c o e f f ic ie n t o f c o r re la t io n between the mean scores

of the two te s ts . Appl icat ion o f the formula above y ie lded a

c o r re la t io n o f 99.6 between the two te s ts , thus ind icat ing

30

tha t the p h o n et ica l ly balanced nonsense s y l l a b le tes ts are as

v a l id a measure o f i n t e l l i g i b i l i t y as are the phon et ica l ly

balanced word te s ts .

This chapter has been concerned with the s t a t i s t i c s

employed in the determination o f the r e l i a b i l i t y and v a l i d i t y

of the newly constructed p h o n e t ica l ly balanced nonsense s y l ­

lab le t e s t . The resu lts o f the inves t iga t ion were also p re ­

sented. The conclusions drawn from these data w i l l be sum­

marized in the fo l low ing chapter.

CHAPTER V

SUMMARY AND CONCLUSIONS

Summary

The present experimentation was undertaken in order

to construct a new te s t for determining speech i n t e l l i g i b i l ­

i t y , using ph on et ic a l ly balanced nonsense s y l la b le s rather

than meaningful words as stimulus m a te r ia l . I t was f e l t th a t

the use o f ph on et ic a l ly balanced nonsense s y l la b le s would pro

vide a more accurate estimate o f i n t e l l i g i b i l i t y by reducing

perceptual cues. The s p e c i f ic questions to be answered con­

cerning t h is t e s t were:

1. Is th is new te s t as r e l i a b l e and v a l i d for te s t in g i n t e l l i g i b i l i t y as the ph on et ica l ly balanced W-22 word test?

2. Does th is new te s t y ie ld lower a r t i c u l a t i o n scores by e l im in a t in g perceptual cues inher­ent in word test ing?

A review of the l i t e r a t u r e revealed tha t there are

many types o f I n t e l l i g i b i l i t y Tests in ex is tence, most of

which use meaningful words as t e s t m a te r ia l . A notable excep

t io n is a t e s t devised by F le tcher and Steinberg (4 ) using

nonsense s y l la b le s instead of words. The descr ip t ion of th is

t e s t indicates that the nonsense s y l la b le s are not phoneti-

c a l 1y balanced.

31

32

The I n t e l l i g i b i l i t y Test constructed for the present

study employed the developmental procedures fol lowed in the

construct ion o f two d i f f e r e n t types o f the tes ts now in e x i s t ­

ence. The stimulus m ater ia ls were o f the nonsense s y l la b le

type as described by F le tcher and Steinberg ( 4 ) . These non­

sense s y l la b le s were ph on et ic a l ly balanced by using the same

phonemes the same number o f times as they were used in the

accepted p h o n e t ic a l ly balanced C * I .D . Auditory Test W-22.

A d i r e c t comparison between the newly formed phoneti­

c a l ly balanced nonsense s y l la b le t e s t and the p h o n e t ica l ly

balanced W-22 word te s t was made by presenting both tests to

ten l is te n e rs at f i v e d i f f e r e n t s ig n a l - to -n o is e r a t io s . The

scores obtained by the ten subjects were s t a t i s t i c a l l y analyzed

in order to t e s t the v a l i d i t y and r e l i a b i l i t y o f the phoneti ­

c a l l y balanced nonsense s y l l a b le te s t as well as the overa l l

leve ls o f a r t i c u la t io n scores for the two types o f te s ts .

Conclus ions

The r e s u l ts o f th is in ve s t iga t ion a l low the fo l lowing

conclusions:

1. The ph on et ic a l ly balanced nonsense s y l l a b le te s t

constructed for th is study is as r e l i a b l e and v a l i d for t e s t ­

ing i n t e l l i g i b i l i t y as are the C . I .D . W-22 te s ts . The Pearson

product moment c o e f f i c i e n t o f c o r re la t io n ca lcu la ted between

the two tes ts produced a c o r re la t io n o f 99 .6 , ind ica t ing high

v a l i d i t y . A high degree of r e l i a b i l i t y was ind icated through

t e s t - r e t e s t procedures which showed a c o r re la t io n of 97 .8 .

33

2. Total perception from minimal cues is la rg e ly

e l im inated when te s t in g w ith nonsense s y l la b le s . A compari­

son o f the a r t i c u la t i o n scores obtained by the subjects on the

two types o f te s ts points out tha t f a m i l i a r i t y with tes t in g

m ate r ia ls does produce markedly higher scores. The scores

obtained on the p h o n et ica l ly balanced nonsense s y l l a b le tests

were considerably lower than those obtained on the correspond­

ing p h on et ica l ly balanced word t e s t .

The compiled s t a t i s t i c a l data fo r th is study a l low the

f in a l conclusion tha t the ph on e t ic a l ly balanced nonsense s y l ­

la b le te s t constructed for th is experimentation compares favo r ­

ably with C. I .D . Auditory Test W-22 in v a l i d i t y and r e l i a b i l ­

i t y . However, i t appears tha t te s t in g w ith words measures

perception as well as i n t e l l i g i b i l i t y . Since the ph on et ica l ly

balanced nonsense s y l l a b l e t e s t e l im inates to ta l perception

from minimal cues, i t is a more v a l id te s t o f i n t e l l i g i b i l i t y .

APPENDIX

PHONETICALLY BALANCED NONSENSE SYLLABLE TEST la

1. ta l 21. hoxid 41. tes

2. sib 22. zam 42. di

3. WjUV 23. r i l 43. wout $

4. SI 24. - tod 44. ta iy

5. kge 25. ts1 45. hwawn

6. PA 26. rera 46. mes

7. zin 27. msez 47. nouk

8. hev 28. Irr 48. l id

■9. na 29. 9ju 49. na

10. reel 30. di v 50. reb

11. Ses 31. l A

12. t A 32. jeed

13. dsaik 33. BA

14. rem 34. te

15. k i f 35. , ren

16. hun 36. toz

17. dait 37. ri6

18. nid 38. t TJ

19. r i 39. tees

20. f ep 40. wig

34

35

APPEND IX (C o n tin u e d )

PHONETICALLY BALANCED NONSENSE SYLLABLE TEST 2a

1. ta d 21 . kon 41. n e s

2. rju b 22. d si 42. . hod

3. t l V 23. rem 43. we

k. r e t 24. t i v 44. lo g

5. r e 25. l e 45. Z33S

6. z ju 26. wed 46. 8 At

7. S^p 27. 6ud 47. ta

8. g i t 28. pom 48. m lz

9. dAf 29. r in 49. h ju s

10. n ot % 30. 611 50. meb

11. vai t 31 . r j u l

12. m z 32. tse

1.3. ka 33. rA

14. wut 34. kus

15. HAS 35. j e

16. r i 36. han

17. l e 37. kai

18. di 38. Wl

19. t e n 39. meb

20. Isen 40. n a id

36

APPENDIX (C o n t in u e d )

PHONETICALLY BALANCED NONSENSE SYLLABLE TEST 3a

1. dA 21. t e f 41 . ni v

2. tod 22. 42. mu6

3. sjus 23. SI 43. sen

4. dssl 24. rse 44. run

5. to ip 25. he 45. 6 i d

6. tov 26. jed 46. tffil

7. djun 27. wem 47. t a i g

8. kA 28. mdy 00 non

9. dank 29. Is 49, wi

10. na 30. web 50. ru

11. t id s 31. 1®

12. f et 32. hi

13. reb 33. r i z

14. hAS 34. r a ik

15. ko 35. tA

16. r a l 36. zlra

17. hwi s 37. re

18. InS

00on san

19. nai 15 39. r i ■

20. z i t 40. taQi

37

APPENDIX (C o n t in u e d )

PHONETICALLY BALANCED NONSENSE SYLLABLE TEST 4a

1. h s t 21. mi 4 ) , kAn

2. d i 22. dsz 42. dut

3. k o it 23. ' dom ; 43 . dgi s

4. ni 24. ruS 44. ro5

5. ma 25. je z 45. jeen

6. wai v 26. ne 46. lu

7. rae 27. tee 47. I i 5

8 o r ju t 28. mas 48. hw ol

9. t a r f 29. lAn 49. d l t

10, hAS 30. l a ib 50. t e

11. ta z 31. wot

12. mev 32. h iy

13. VI 33. l a l

14. t^un 34. se

15. hwe 35. 01

16. k ig 36. rap

17. nok 37. nes

18. r i z 38. rem

19. dm s 39. rxi

20. natrt 40. ret)

38

APPENDIX (C o n t in u e d )

PHONETICALLY BALANCED NONSENSE SYLLABLE TEST lb

1. dap 21. ta1! 41. nai d2. lib 22. nez 42. gan3. nu 23. kA 43. dA4. mi 24. ro$ 44. ron5. wi© 25. ved 45. wai s6. re 26. la 46. haut7. t ju 27. r it 47. veb8. VIS 28. lep 48. zut9. hin 29. wid 49. lot

10. raik 30. zit 50. to811. IQA 31. jAS12. tuio 32. ral ,13. ke5 33. t$i14. ne8 34. nok15. fi 35. hwat16. ta 36. ma17. rse 37. di18. zem 38. dges19. njuf 39. run20. mas 40. hes

REFERENCES

1. Black, J. W, , M u l t ip le -c h o ic e i n t e l l i g i b i l i t y te s ts .J. Speech Hearing P is . , 22, 1957, 213-235.

2. Dewey, G . , R e la t iv Frequency o f English Speech Sounds.London: Humphrey M i l fo r d , Oxford U n iv e rs i ty Press.Cambridge: Harvard U n ivers i ty Press, 1931.

3. Fairbanks, G . , Test o f phonemic d i f f e r e n t i a t i o n : theRhyme Test. J. Acoust. Soc. Amer. , 30, 1958, 596-600.

4. F le tcher , H. and J. C. S te inberg , A r t ic u la t io n tes t ingmethods. Bell Svst. Tech. J . , 8 , 1929, 806-854.

5. French, N. R . , C. W. Carter and W. Koenig, The words andsounds o f telephone conversations. Bel 1 * Svst .Tech. J . , 9, 1930, 290-324.

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7. H irsh , I . J . , H. Davis, S. R. Silverman, E. G. Reynolds,E. E ld e r t and R„ W. Benson, Development o f m ater ia lsfor speech audiometry. J. Speech Hearing P is . , 17, 1952, 321-337,

8 . Kantner, C. E. and R. West, Phonetics. (Rev. E d , ) NewYork: Harper and Brothers, 1960 .

9. Kenyon, J. S. and T, A. Knott, A Pronouncing D ic t ionaryo f American Engl ish . S p r in g f ie ld , Massachusettst G. and C. Merriam Co., 1944.

10. Newby, H . , Audioiogy; P r in c ip le s and P r a c t ic e . New York:Appleton-Gentury-Crofts , I n c . , 1958.

11. Thorndike, E. L. and 1. Lorge, The Teachers Word Book o f30,000 Words. New York: Columbia U n iv e rs i ty Press,l a t e ---------------

12. Underwood, B, J . , C. P. Duncan, J . A. Taylor and J. W.Cotton, Elementary S t a t i s t i c s . New York: Appleton-C en tu ry -C ro f ts , I n c . , 1954.

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