AN EVALUATION OF TWO -TYPE TESTS OE

Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

By

THOMAS BROWN ANDERSON, B.S., M. S. The Ohio State University 1952

Approved by: TABLE OE CONTENTS CHAPTER

I. INTRODUCTION ...... 1

The Problem...... 7 The Hypotheses ...... 8 Explanation of Terms ...... 12

II. REVIEW OE LITERATURE ...... 14 III. PROCEDURES...... 26 Apparatus...... 26 Stimuli...... 28

Subjects ...... 29 Presentation ...... 30

Scoring of Tests ...... 33

IV. RESULTS AND DISCUSSION...... 34

Part I ...... 34 Part II ...... 96

V. CONCLUSIONS ...... 99 BIBLIOGRAPHY...... 104 APPENDIX A ...... 108 APPENDIX B ...... 110 APPENDIX C...... 111 APPENDIX D ...... 112

APPENDIX E ...... 113 APPENDIX E ...... 114 AUTOBIOGRAPHY ...... 115

ii E09365 LIST OE TABLES TABLE PAGE I. Order of Tests for Each. Group of 10 Subjects . 27 II. Analyses Made and Statistical Methods Used . . 36 III. Summary of Tests of Independence and Correla­ tion of Pure-Tone Scores and Speech- Reception Scores ...... 38 IV. Summary of Eight Analyses of Variance: Measures of Listeners Scores for the Pure-Tone Test and the Multiple-Tone Pulse-Type Test (monaural)...... 43 V. Mean Scores in Decibels for the Pure-Tone Tests for Six Levels of Scores for the Multiple-Tone Pulse-Type Test...... 44 VI. Mean Threshold Values (Relative db) of Pure Tones Associated With That are Categorized 5”0 on the Multiple-Tone Test. 47 VII. Summary of an .Analysis of Variance: Measures of Scores for the Speech-Reception Test and the Multiple-Tone Pulse-Type Test. . • 52 VIII. Mean Scores for the Speech-Reception Tests in Three Levels of the Multiple-Tone Pulse-Type Test...... 53 IX. Results of Bi-Serial Correlations for Measurements of Binaural Speech-Reception Scores and the Multiple-Tone Pulse-Type Test Under Two Laboratory Conditions . . . 55

iii LIST OF TABLES (Cont’d.) TABLE PAGE X. Mean Scores of the Multiple-Tone Pulse-Type Test and Retest in Two Categories of Scores for the Speech-Reception T e s t ...... 56 XI. Summary of an Analysis of Variance: Measures of Listeners Scores of the Multiple-Tone Pulse-Type Test and the Speech-Reception Test. 58 XII. Contingency Tables for the Chi-Square Test of Independence of the Multiple-Tone Pulse- Type Test Under Two Conditions ...... 61 XIII. Contingency Tables for the Tetrachoric Correlations of the Multiple-Tone Pulse- Type Test Under Two Conditions...... 63 XIV. Contingency Tables for the Chi-Square Test of Independence of the Multiple-Tone Pulse- Type Test Under Controlled Conditions and the Original Multiple-Tone Pulse-Type Test With Zero Scores Removed * ...... 66 XV. Summary of Eight Analyses of Variance: Measures of Listeners Scores for the Sihgle- Tone Pulse-Type Test and the Pure-Tone Test. . 70 XVI. Summary of Eight Analyses of Variance: Measures of Listeners Scores of the White- Noise Pulse-Type Test and the Pure-Tone Test • 71 XVH. Mean Score Values for the Pure-Tone Test in Seven Levels of Scores for the Single-Tone Pulse-Type and the White-Noise Pulse-Type Test (monaural)...... 72

iv LIST OF TABLES (Cont'd.) TABLE PAGE XVIII. Summary of Four Analyses of Variance: Measures of Listeners Scores of the Single- Tone Pulse-Type Test (binaural) and the Pure-Tone Test Scores for the Better . . 79 XIX. Summary of Four Analyses of Variance: Measures of Listeners Scores for the White- Noise Pulse-Type Test (binaural) and the Pure-Tone Test Scores for the Better Ear • • 82 XX. Mean Scores of Seven Levels of Scores for the Single-Tone and White-Noise Pulse-Type Test (binaural) and Pure-Tone Test Scores

for the Better E a r ...... 86 XXI. Contingency Tables for the Chi-Square Test of Independence of Speech-Reception Scores and the Single-Tone Pulse-Type and White- Noise Pulse-Type Test (binaural)... 91 XXII. Contingency Tables for the Chi-Square Test of Independence of Speech-Reception Scores and the Single-Tone Pulse-Type and White- Noise Pulse-Type Test (binaural-retest)... 95 XXIII. Mean Scores of the Multiple-Tone Pulse-Type Test for Both Ears in Six Levels of Noise. . 98

v LIST OF FIGURES FIGURE PAGE 1. A Graphioal Representation of the Relationship Between the Mean Scores of the Pure-Tone Test and Scores Yielded by the Multiple-Tone Pulse- Type Test ...... 48 2. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test and Scores Yielded by the Multiple-Tone Pulse- Type T e s t ...... 49 3. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test and the Combined Scores for Both Ears Yielded by the Multiple-Tone Pulse-Type Test...... 50 4* A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test and the Combined Scores for Both Ears with One Score Computed as Weighted Means for Four Scores Yielded by the Multiple-Tone ( Pulse-Type T e s t ...... 51 5. A Graphical Representation of the Relationship Between the Mean Scores of the Speech-Recep­ tion Test and Three Classifications of Scores as Yielded by the Multiple-Tone Pulse-Type T e s t ...... 54

6 . A Graphical Representation of the Relationship Between the Mean Scores of the Speech-Recep­ tion Test and Three Classifications of Scores for the Better.Ear as Yielded by the Multiple- Tone Pulse-Type Test...... 59 7. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test for the Left Ear and Scores for the Left Ear as Yielded by the Single-Tone Pulse-Type Test. 73 S'. A Graphical Representation of the Relationship » Between the Mean Scores of the Pure-Tone Test for the Right Ear and Scores for the Right Ear as Yielded by the Single-Tone Pulse-Type Test...... 74

vi LIST OF FIGURES (Cont’d.) FIGURE PAGE

9. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test for the Right Ear and Scores for the.Right Ear as Yielded by the White-Noise Pulse-Type Test. . 75 10. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test for the Left Ear and Scores for the Right,Ear as "Yielded by the White-Noise Pulse-Type Test. . 76 11. A Graphical Representation of the Total Number of Correct Responses on Repeated Tests of the Single-Tone Pulse-Type and White-Noise Pulse- Type T e s t s ...... 81 12. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test for the Better Ear and Scores as yielded by the Single-Tone. Pulse-Type Test (binaural) . . . 83 13. A Graphical Representation of the Relationship Between the Mean Scores of the Pure-Tone Test for the Better Ear and Scores as Yielded by the White-Noise Pulse-Type Test (binaural) ...... 84 14. Obtained per cent Right Scores on Multiple-Tone Pulse-Type Test for the Left Ear in Six Levels of White Noise; also Line of Best Fit. Left Ear. §7 15. Obtained per cent Right Scores on Multiple-Tone Pulse-Type Test for the Right Ear in Six Levels of White Noise; also Line of Best Fit. Right Ear. 08

vii AN EVALUATION OE TWO PULSE-TYPE TESTS OE HEARING CHAPTER I INTRODUCTION

Many clinical tests have been used in assessing hearing ability. Some are relatively new; others are of long standing. Some older tests as the conversational- voice test, the whisper test, the watch-tiek test, and the 1 coin-click test continue to be used.

"Slallowell Davis, Hearing and , (New York: Murray Hill Book, Inc., 1947, P« 126.

The Voice Test Goldstein, writing in 1924, stated that voices vary so greatly in pitch, in intensity, and character that it is impossible to formulate an absolute standard for testing and therefore approximate standards must suffice in the administration and interpretation of both conversational 2 voice and whisper. Various clinical tests with voice have

2 Max A. Goldstein, "Functional Tests of Hearing," Oralism and Auralism, 3:2, 1924. been made. Kopetsky describes a voice and whisper test 3 that is used today. The normal distance for this test 3 S. J. Kopetsky, Deafness, , and , (New York: Thomas Nelson and Sons, 1948), pp. 164-171.

1 2 for the conversational voice is 20 feet and for the whispered voice is 15 feet. He notes the obvious sources of error in this method and concludes that for measurements of hearing losses in the "speech range" of sound frequencies, the voice and whisper tests have little scientific value. However, he states that since the ability to hear normal speech is the prime interest of the deafened patient, speech tests should be used with better methods of control.

The Watch Test The watch test is still used occasionally. Goldstein claimed that this test has an advantage over the older voice test in that the watch tick does not vary from time to time in intensity or pitch of its tick and can therefore be better standardized than the voice.^ Again the test depends upon

4 Goldstein, 0£. cit., p. 5.

testing conditions and type of watch if the test is to be standardized. Fletcher shows the inaccuracy of this test in that the watch and coin click tests are mostly in the

high frequency region, around 2 ,0 0 0 c.p.s. (cycles per second) and hence more reflection patterns are produced in 5 a room than for the low frequencies.

5 Harvey Fletcher, Speech and Hearing. (New York, D. Van Nostrand Co., Inc., 1929, p. 206 . 3 Other Early Tests Another attempt at hearing testing was by Politzer's Acoumeter. The idea of this instrument was an attempt at control of the intensity of sound as it is produced for testing hearing. The Monochord and the G-alton Whistle were also attempts at methods of testing. The Galton Whistle was designed to produce sounds ranging from 4,000 to 25,000 c.p.s. The Monochord was designed to be a substitute for high-pitched tuning forks and the Galton Whistle. The administration of the test was very time consuming.

Tuning Forks According to Bunch, tuning forks have played an impor­ tant part in the development of otology.^ He states:

6 Gordia C. Bunch, Clinical , (St. Louis: G. V. Mosby G o c , 1943), p^ T5Z

Its progress under the leadership of those who described them and indicated their clinical signi­ ficance is the best evidence of their practical value and the advent of the electric audiometer is not in itself an argument for discontinuing their use. The most widely used of the fork tests are the Weber, Rinne, and Schwabach tests. They were developed in 1834,

1 8 5 5 , &hd 1890 respectively and are widely used by otologists as aids in diagnoses of types of hearing impairment. The Audiometer Audiometry itself is not a new term. Bekesy reports that the first audiometric measurements are apparently attri- 7 butable to Sauveur in 1700. Sauveur used organ pipes to

f f George Ton Bekesy, "The Early History of Hearing Observations and Theories," Journal of the Acoustical Society of America. 20:727-748, November, 194&. test the frequency limits of hearing and he set the limits at 12.5 c.p.s. and 6,400 c.p.s. In 1820, Wollaston made the first set of measurements that compare reasonably well with our present day data. He established the limits of hearing at 30 c.p.s. and 18,000 c.p.s. Bunch states that lack of standardization (of watch tests, tuning forks, etc.) has been one of the chief reasons 8 for the development of the electrical audiometer. However,

Bunch, op. cit.. p. 27. a Committee for the Consideration of Hearing Tests reported in 1933: As oscillometers the present audiometers are scien­ tifically accurate. It is in their application to clinical otology that they have failed, and that re­ sults obtained differ from those obtained from tuning forks. The results of testing by tuning forks have been for many years and still are the standard in otology, and until audiometry gives results directly comparable with them, theyqcannot be accepted as a standard means of testing.y

Report of The Committee for the Consideration of Hearing Tests, Journal of Laryngology and Otology. 48:22-48, 1933. 5

There were many early attempts at perfecting an elec­ trical audiometer. Many of the early audiometers were too costly or bulky to be practical. According to Bunch, the first vacuum-tube audiometer to become available commercially was the Western Electric 1-A. However, it was both bulky and costly and few were produced. In referring to the audio­ gram, he says: The charts and hearing curves were called audio­ grams, and being defined as a curve plotted so as to show the variation of minimum audible sensi- tivityAwith frequency where the stimulus is a pure tone.

10 Gordia C. Bunch, "History of Development of Audio­ metry," Laryngoscope. 51:1100, 1941*

Since these early audiometers came into use, several types of pure-tone and speech audiometers have been developed. They have come into wide use in schools, hospitals and speech clinics, as means of determining hearing acuity. Such terms as detection threshold, audiogram, speech reception threshold. for speech, average db loss, AMA per

#• cent loss for speech, and others are well known to those who test hearing. So, the search continues for still better ways of expressing the various aspects of hearing, for as Kopetsky says, There is, at the present state of our knowledge, an inherent difficulty in the functional tests of hearing acuity. This is due to the fact that in \ most of our methods of testing the cooperation of the patient is necessary.-1-1 6

11 Kopetsky, op. oit.. p. 1 6 7 *

Generally speaking, however, testing by speech and audiometry are consider edr two of the principal means of determing hear­ ing loss, especially among large numbers of people as in school populations. In referring to audiometry, Dahl states: The discrete frequency threshold test, when compe­ tently administered, is the most accurate and de­ scriptive type of auditory acuity measurement avail­ able. The test is used primarily as a final check on results of previous, more rapid screening tests and as a basis for educational and medical referral.

12l. a. Dahl, Public School Audiometry. (Danville, Illinois: Interstate Publications, 1 9 4 9), pT 118.

The study that is reported here was made using some of the current techniques of testing hearing.

v 7 THE PROBLEM

The purpose of this study was to evaluate two pulse- type tests that have been developed as screening tests for hearing acuity. One of these, a multiple-tone pulse-type test, was devised by the experimenter as a screening test for the frequency region most important in understanding speech.^

1 Hallowell Davis, Hearing and Deafness, (New York: Murray Hill Books, Inc., 1947), p. 1251

The test, including instructions, requires one minute for administration. It was designed as a screening test to be used as part of the for men during Orientation Week at The Ohio State University. Two require­ ments were set up for this testing situation: (l) that the

test take no longer than 45 seconds per student and (2 ) that it adequately tests the frequencies most important in under­ standing average conversational speech. The test was admin­ istered in sound-treated booths (Appendix A) that were erected temporarily in one corner of the M e n ’s Gymnasium and at the end of the examination line. The ambient noise levels inside the booths in this situation ranged upward to

6 5 db as measured by the General Radio sound level meter Model 759 (Scale C). The second test which was evaluated was devised under contract by the Ohio State University Research Foundation at 8 the School of* Aviation Medicine, Naval Air Station, Pensacola, Florida. It included two parts, a single-tone pulse-type part and a white-noise pulse-type part. The test was designed specifically to indicate the extent of loss of hearing that comes with exposure to high level noise. However, in this study, it is evaluated as a screening test for hearing acuity. The two parts are administered in quick succession as a single testing experience and have the following in common:

(1 ) each contains a succession of test events that are attenuated in two-decibel steps; (2 ) each has from two to four per event. Through varying the number of pulses per event, alternative forms of the test are provided; (3 ) each is given under identical conditions; and (4 ) each form is scored alike. In order to evaluate these tests, both the multiple- ton8 pulse-type test and the single-tone pulse-type and white- noise pulse-type test were compared with a speech-reception test and a pure-tone audiometric-type test.

HYPOTHESES In order to evaluate the two tests under investigation, the following nine hypotheses were formulated and tested. > Hypothesis I. Scores of the pure-tone test were categorized on the basis of perfect and imperfect. The speech-reception test *

scores were categorized into higher half of scores and lower 1 9 half of scores. On the basis of these classifications, the two tests are unrelated as measures of hearing acuity.

Hypothesis II. Subjects were grouped according to their scores on the multiple-tone pulse-type test. On the basis of pure-tone scores for a given frequency for a particular ear (right- left) , there is no difference in the means of the groups.

Hypothesis III. Subjects were grouped according to three categories of the multiple-tone pulse-type test. On the basis of speech' reception scores, there is no difference in the means of the groups.

Subjects were grouped according to categories of perfect and imperfect scores of the multiple-tone pulse-type test. On the basis of speech-reception scores, there is no difference in the means of the categories.

Hypothesis IV. Scores of the original multiple-tone pulse-type test and scores of the same test in laboratory conditions were categorized on the basis of perfect and imperfect. On the basis of these categories, the two tests are unrelated as measures of hearing acuity. 10 Hypothesis V . Scores of the multiple-tone pulse-type test and retest under laboratory conditions were categorized on the basis of perfect and imperfect. On the basis of this classification, the tests are unrelated as measures of hearing acuity. i Hypothesis VI. Subjects were grouped according to scores made on the single-tone pulse-type and white-noise pulse-type tests for each ear. On the basis of pure-tone scores for a given fre­ quency for a particular ear (right-left), there is no differ­ ence in the means of the groups. <

I Hypothesis VII. Subjects were grouped according to scores made on the single-tone and white-noise pulse-type tests administered i binaurally. On the basis of pure-tone scores for the better ear for a given frequency, there is no difference between *" i the means of the groups.

Hypothesis VIII. Scores of the single-tone and white-noise pulse-type tests were separated as near the median as feasible into two groups. The same was done for scores of the speech-reception tests. On the basis of these categories, the two tests are unrelated as measures of hearing acuity. 11

Hypothesis IX* Scores on the retest of the single-tone and white- noise pulse-type tests were separated as near the median as feasible into two groups. The same was done for scores of the speech-reception tests. On the basis of these categor­ ies, the two tests are unrelated as measures of hearing acuity. 13 period for each, man was approximately one and one-half hours. Pure-tone audiometric-type threshold test: A,test for the detection of the frequencies 500, 1 ,0 00, 2,000 and

4,000 c.p.s. just audible to a listener when these tones were produced at the ear through earphones monaurally. Speech-reception test: A word test (Harvard Auditory Test #14, Forms A,B,C, and D) given in free-field conditions which determines a listener’s ability to understand speech. The level (db) of presentation at which the listener repeats

correctly 50 per cent of the words is considered the speech- reception threshold. period for each man was approximately one and one-half hours. Pure-tone audiometric-type threshold test: A,.test for the detection of the frequencies 500, 1 ,0 0 0 , 2 ,000 and

4,000 c.p.s. just audible to a listener when these tones were produced at the ear through earphones monaurally. Speech-reception test: A word test (Harvard Auditory Test #14, Forms A,B,C, and D) given in free-field conditions which determines a listener's ability to understand speech. The level (db) of presentation at which the listener repeats correctly 50 per cent of the words is considered the speech- reception threshold. CHAPTER II. REVIEW OF LITERATURE

Although several studies have evaluated various types of hearing tests, none has treated directly the two that are evaluated in this study. Some of the earlier studies do, however, relate to the types of tests under investiga­ tion as well as to two tests that are used as criterion measures in the present analyses. There has been some controversy concerning the rela­ tionship of speech tests and . Guilder reported high correlation between hearing tests for speech and the audiogram..'*' She found in comparing audiometric and word

1 Ruth P. Guilder, "Audiometric and Word Test Findings- Preliminary Report," Annals of Otology, Rhinology, and Laryngology, 52:25-33, 1943. tests that the audiogram is a clear indication of an indi­ vidual's ability to hear speech and "any deviations in the graph at any point between 90 and 8 ,0 0 0 c.p.s. are usually reflected in some dimunition in the individual hearing of speech." Hughson and Thompson reported results of research to determine the relationship between practical disability in understanding speech imposed by hearing losses and the 2 thresholds of hearing for pure tones. They concluded that

- W. Hughson and E. Thompson, "Correlation of Hearing Acuity for Speech with Discrete Frequency Audiograms," Archives of Otology, 36:526-540, October, 1942. 15 the relation between audiometric percentage losses and im­ pairment of speech reception is definite and specific. In comparing the audiogram with the speech reception threshold, these investigators found that frequencies above and below

512 - 2 , 0 4 8 c.p.s. have little significance in the subjects1 ability to understand speech. Harris in summarizing data bearing on the relative usability of the free voice and pure-tone audiometry found that the concensus of studies was that a careful voice test and pure-tone audiometry through the speech range (5 0 0 -2 ,0 0 0 c.p.s.) are intimately connected and measure almost the same 3 function. The comparison of six studies reveal the rela- 3 J. Donald Harris, "Free Voice and Pure Tone Audio­ meter for Routine Testing of Auditory Acuity,” Archives of Otolaryngology, 4 4 :4 5 2 - 4 6 7 » October, 1946. tionship between the two tests to be a straight line function. However, all writers do not agree with these reports.

Kinney published a paper in 1 9 4 1 o n the relationship of 4 hearing for speech and pure tone thresholds. He reported

— Charles E. Kinney, "Testing Hearing and Evaluation of Results in Mathematical Figures,” West Virginia Medical Journal, 37:448-453» October, 1941. that when the Eustachian tube was inflated in cases of chronic catarrhal deafness and healing cases of otitis media, hearing for speech improved without any change in the audiogram. McFarlan tested the hearing of twenty-two subjects with pure 16

5 tones and with the Western Electric phonograph audiometer.

5 Douglas McFarlan, "Speech Hearing and Speech Inter­ pretation Testing,” Archives of Otology. 31:517-523, 1940.

Results showed that the pure tone audiogram indicated a greater loss than the phonograph test. Trowbridge made comparative studies of some commonly used hearing tests (voice and whisper, audiometer, tuning \ 6 forks). The correlation of their results indicated that one 6 Barnard C. Trowbridge, "Correlation of Hearing Tests," Archives of Otolaryngology. 45;319-334, 1947* is not justified in drawing precise conclusions concerning deficiency from these methods as now employed. The whisper voice test as a regulation test for the hearing of those entering military service should be supplemented by . The testing of hearing acuity by controlled speech tests received against a background of measured noise would seem to give an additional evaluation of hearing acuity and efficiency. Fletcher has done a considerable amount of research in the relationship between sensation units of hearing loss 7 and the maximum hearing distances for speech. He lists 7 Harvey Fletcher, Speech and Hearing, (New York: D. Van Nostrand Co., Inc., 1929) p. 204. tables for hearing a whisper and three levels of voice at various sensation units of hearing loss. The data seem to 17 exemplify the "inverse square law.” Carhart, in a study of voice as a measure of hearing, studied: (l) the correlation between loss for pure tone and loss for speech reception; (2 ) the degree to which a person may predict the loss according to one type of test from the loss as measured by the other type; and (3 ) the relative 8 reliabilities of the two tests. He reported that speech — Raymond C. Carhart, "Monitored Live Voice as a Test of Auditory Acuity," Journal of the Acoustical Society of America. 17039-349, April, 1945*. words and the 512-1 ,0 2 4 -2 ,0 4 S cycle frequencies are inter­ dependent. He also found that the numerical correspondence between the two types of measures, as gauged by group means and standard deviations is relatively good. However, a sizable margin of uncertainty affected the precision dis- advantageously with which one type of score can be predicted from another. The speech-reception method, when conducted properly, gives acceptable measures of hearing loss and is of particular value when used in combination with pure-tone audiometry. In another study Carhart studied the relationship between loss for speech reception and loss for pure tones to determine if speech reception varied with the contour of g the audiometric curve. He found high positive correlation ’ ~ Raymond Carhart, "Speech Reception in Relation to the Pattern of Pure Tone Loss," Journal of Speech and Hearing Disorders, 11:97-10S, June, 1946. 18

except for cases with marked high-tone loss. Along this same line, Fowler states that because of wide differences in ears and "word deafness,” the air con­ duction threshold audiogram is not sufficient for measuring 10 hearing capacity. 10 E. P. Fowler, Sr., ”Is the Threshold Audiogram Sufficient for Determining Hearing Capacity?", J~ournal of the Acoustical Society of America, 15:60, July, 1943*

Beasley conducted a study in which eight tones were tested by air conduction and concluded that the correlation between hearing losses by air conduction and hearing capacity 11 for speech is extremely high. He says that both screening

—- Willis C. Beasley, "Correlation Between Hearing Loss Measurements by Air Conduction on Eight Tones," Journal of the Acoustical Society of America. 12:104, July, 1940.

and clinical types of audiometers, any one of these four

tones (5 0 0 , 1 ,0 0 0 , 2 ,0 0 0 , and 4 ,0 0 0 c.p.s.) provides approxi­ mately equal predictive value as to the acuity of hearing throughout the range. Correlation between hearing losses

at 1 ,0 2 4 c.p.s. and 2 ,0 0 0 c.p.s. was found to be higher for females than for males. Since either tone is about equally predictive of the ability to hear speech, he concludes that

a tone in the region of 2 ,0 0 0 c.p.s. is preferable. Steinberg and Gardner published results of the possible ^ 1 o effects of recruitment on the perception of speech. The ~~ ^ ■ Recruitment is defined as the condition where faint or moderate sounds cannot be heard while at the same time there is little or no loss in the sense of loudness of loud sounds, (Davis et al, Hearing and Deafness. New York: Murray Hill Books, 1947, P* 71.) 19

12 J. C. Steinberg and M. B. Gardner, "On the Auditory Significance of the Term Hearing Loss," Journal of the Acoustical Society of America, 11:270-277> January, 19AO, authors conclude: The audiogram is not an accurate indication of hearing impairment for above threshold sounds in cases involving nerve deafness when the loss in loudness sensation is taken as the criterion; but when the capacity to interpret speech sounds, as indicated by the articulation tests, is the criter­ ion, the audiogram does give an approximately correct indication of the hearing impairment. In schools, many thousands of students have been tested. The problem has been to "screen out" those with hearing defects. Screening is done by setting the hearing loss dial of a pure-tone audiometer at a faint level within the normal hearing range and rapidly checking the frequency range. The subject indicates if he hears the tones at the different frequencies. According to Watson, normal hearing through a part of the frequency range with a tonal dip at 13 some point may quickly be discovered. Moreover, it is 13 Leland A. Watson and Thomas Tolan, Hearing Tests and Hearing Instruments, (Baltimore: The Williams and Williams Co., 1949), p. 2 3 4 .

a rapid method for separating those In large populations who have no hearing loss. Gardner describes a pulse-tone type test used as a 14 basis of the 1939-40 Worlds Hair tests. It has been 14 M. B. Gardner, "A Pulse-Tone Technique for Audio­ metric Threshold Measurement," Journal of the Acoustical Society.of America, 19:592-599, July, 1947. 20 adapted to clinical audiometric use. For this purpose a tri-functional control has been utilized consisting of (1) an electronic method of producing the desired number of tone- pulses in a selected sequence under control of the operator, (2) a visual signal which occurs at the beginning of each pulse-series to act as a warning to the observer, (3) a visual signal which flashes in synchronization with the out­ put tone-pulses to act as a counter for the operator. Three out of four testers expressed a desire for this over regular tests. However, it takes longer to administer than the usual methods.

Speech Reception Testing. In recent years a number of speech tests have been devised for measuring various aspects of hearing for speech. One of the best known of these has been the Harvard Word Lists developed by the Psycho-Acoustic Laboratory of Harvard University. These lists and others, have come into popular use for measuring various "thresholds" of speech. Egan, in writing about speech reception tests, says that there are three different speech reception thresholds to consider: (l) the thresholds of detectability, (2) the threshold of perceptibility, and (3) the threshold of in- 15 telligibility. He differentiates between them in the 15 lames B* Egan, "Articulation Testing Methods II," Research on Sound Control, Psycho-Acoustic Laboratory, Harvard University. OSRD Report #3^02, Project NA-10S. November, 1944, P» 5&. 21 following manner: (1) The threshold of detection is the point at which the subject is just able to detect the presence of speech sounds about one-half the time but unable to identify any of the sounds themselves. (2) The threshold of perceptibility is the point at which if speech were made more intelligible, one could with little or no effort understand it, and if the speech were made less intelligible, he could not perceive a sufficient number of words to allow him to follow the main idea of the passage read to him. Egan reports deviation in measuring thresholds of percepti­ bility in thirty cases from 1.3 d.b to 1.7 db. In regard to the threshold of intelligibility, he states: (3) The listener adjusts some variable until In his judgement, he is just able to obtain without perceptible effort the meaning of almost every sentence and phrase of the connected discourse read to him. Davis states that the normal threshold of intelligi­ bility lies some 15 or 20 db above the normal threshold for , 16 pure tones. 16 Hallowell Davis, et al, ”The Selection of Hearing Aids,” Laryngoscope, 56:139, March-AprII, 1946.

Watson writes that spondaic words as in the Harvard Test #9 are the most useful material for speech reception threshold tests, whether recorded at a constant level or 17 attenuated. 17 Watson and Tolan, op. cit., p. 447- 22

In discussing spondaic type words, .Egan states: The class of words having the highest homogeneity contained those di-syllables spoken with equal stress on both syllables. These words are called spondees. . . . . The words . . . have proved particularly useful in tests whose purpose is to establish accur­ ately the amplification or power level at which speech can be heard. These homogeneous words reach the threshold of hearing with precision. In partic­ ular, the lists of spondees have been recorded phonographically for use as an audiometric test in the measurement of deafness .... The level at which he hears half the words is usually considered the threshold of hearing for speech.

Egan,. op.. cit.. p. 23.

Breakey and Davis administered the Harvard Auditory Tests #9 (words) and #12 (sentences) to 10 normal hearing subjects and 10 hard of hearing subjects. 19 The hard of hearing group was tested monaurally and binaurally through

19 Margaret Breakey and H. Davis, "Comparisons of Thresholds for Speech: Word and Sentence Tests; Receiver vs Field, and Monaural vs Binaural Listening," Laryngo­ scope . 59: 236-250, March, 1949. earphones and the normal hearing group, binaurally from a loudspeaker. Free-field listening showed a mean threshold for the two tests lower by 2.88 ± . 47 db than receiver listen­ ing. By earphone listening the threshold for Test #12 was 6 .6 4 ^ . 7 3 db higher than for Test #9 for the normal hearing group. For the binaural tests the two ears of the normal group were not equated for differences in sensitivity. However, for earphone listening, the subjects with normal hearing showed a significant advantage of 2 .2 5 db for binaural 23 listening over the average of all monaural thresholds and of 1.4 db over the mean threshold for the better ear. The hard of hearing listeners showed a mean advantage of 3*25 db for binaural listening over monaural when the listeners two ears, were equated in sensitivity. The mean threshold of the normal hearing group for PB words was about 11 db higher than their mean threshold for Test #9. Pollack conducted a study on binaural and monaural 20 thresholds using tones and noise. The study revealed

20 : ' I. Pollack, ,fMonaural and Binaural Threshold Sensi­ tivity for Tones and for White Noise, tr J ournal of the Ac oust i ceil Society of America, 20:52-57, January, 191+8, that the auditory threshold is not constant and equal to the sum of the effective acoustic powers at the two ears. For the 1 0 0 0 -cycle tone the binaural thresholds were found to be significantly lower than the monaural thresholds when the two ears were equated in sensitivity. The differences between monaural and binaural thresholds were found to be significantly greater for pure tones than the corresponding differences for the noise.

Multiple Pure-Tone Tests According to Watson and Tolan, multiple pure-tone 21 testing is being done successfully. Harris described a

21 ’ ’ Watson and Tolan, o p . cit., p. 266. 24 technique in which, tone spurts were delivered at various frequencies at an initial intensity of 30 db above threshold, 22 one-half second duration. Phillip Johnston has developed 22 D. J. Harris, "Group Audiometry," J ournal of the Acoustical Society of America, 17: 73-76, July, 1945*

23 what is known as the Massachusetts Test. It is a pure tone, 23 P. W. Johnston, "The Massachusetts Hearing Test," J ournal of the Acoustical Society of America, 20: 697-703, September, 19 4*3. manually operated test which, according to Johnston, has an advantage over the phonograph type of audiometer test in that the operator can avoid testing in sporadic noisy condi­ tions. It is a combination speech-pure-tone group test technique in which standard phonograph speech audiometer equipment is converted for dual testing use by the addition of a discrete frequency audiometer and a coupling unit. The group pure-tone section of the test is shown to possess a marked superiority over the phonograph test in terms of correlation with individual pure-tone test criteria. Reger and Newby describe a multiple pure-tone test in which tones are delivered according to a pre-arranged pattern one, two, or three times at various levels of sound 24 pressure and frequency. A light is turned on simultaneous­ ly with the tone signal delivery to provide proper sychroni-

— S. N. Reger and H. A. Newby, "A Group Pure Tone Hearing Test," J ournal of Speech and Hearing Disorders, 12: 61, March, 1947. ______

zation. 25

Watson developed a multiple-tone test in 1948 to be 25 used with the phonograph type audiometer. Recorded tone signals from one to four in number are delivered at inten- — Watson and Tolan, op. cit., p. 267. sities of 3 0 , 2 0 , 1 0 , and five db above threshold. The two tests evaluated in this study were pulse-type tests. Pure-tone and speech-reception tests were used as criterion measures in evaluating them. CHAPTER III PROCEDURES

This study was conducted to evaluate two pulse-type hearing tests. To test the hypotheses involved comparison of four tests, the two under study, and two which are generally accepted as accurate measures of hearing, that is, a speech-reception test and a pure-tone audiometric-type test. The subjects for this experiment were given the four tests as well as an additional multiple-choice word test which is not included in this study. The order of tests for each group of 10 subjects is shown in Table I.

APPARATUS The plan of the study was experimental. It required (1 ) equipment to control the signals both free field and

through ear phones and (2 ) a sound-treated room in which there would be no extraneous noise to interfere with the tests. The following equipment was used: 1. The sound-treated room with an ambient noise level of 30 db (General Radio Sound Level Meter, Model 759, A Scale). 2. One Series 800 ”Voice-of-the-Theater” (Altec- Lansing Co.) speaker.

26 TABLE I ORDER OF TESTS FOR EACH GROUP OF 10 SUBJECTS

Subjects Test Form Test Test Form Test Test Form Test Test Form Test Test Form Test Order Order Order Order Order 1 I 1,2,3 bLR II L R III L R IV b X A b 2 X 2 b I 3,1,2 bRL II R L III R L IV B b 3 IV C b X 3 b I 2,3,1 L R II L R III L R 4 III R L IV D b X 4 b I 4,5,6 bRL II R L 5 II L R III L R IV A b X 1 b I 6.4,5 bLR 6 X 2 b IV B b III R L II R L I 5.6A bRL 7 IV C b III L R II L R I 1,2,3 bLR X 3 b 8 III R L II R L -I 3,1,2 bRL X 4 b IV D b 9 II L RI 2,3,1 bLR X 1 b IV A b III L R 10 .1 4,5,6 bRL X 2 b IV B b III R LII R L

Key: I— Single tone pulse-type and white noise test. II— Multiple tone pulse-type test III— Pure tone test IV— Speech, reception test X— Multiple choice speech reception test (not evaluated in this study) b— Binaural 1,2,3, - 4,5,6— Forms of test L-R— Left - Right A-B-C-D— Forms of speech reception test (IV) I— For retest of this test, forms other than those of the first test were used. II— For retest of this test, identical form was given 10 db lower than first form. r

28

3. One Daven Attenuator, 110 db. 4« Two sets of Permoflux PDR-3 earphones. 5. One Presto Transcription Turntable with a Pickering 190 professional tone arm. 6. One pure-tone discreet frequency audiometer. 7. One General Radio Sound Level Meter, Model 759. 8 . Four 16-inch records containing the four

separate tests used in the study (33 1 /3 rpm).

Calibration of test levels for the multiple-tone pulse type test was done by matching as closely as possible the level of the test tones for the multiple-tone pulse-type and pure tones from the audiometer. The instructions for the multiple-tone pulse-type test were recorded at approximately 20 db more intensity than the test tones. The pulse-tones were one-half second in duration. Calibration of the single-tone pulse-type test and the white-noise pulse-type test was by a like method with the final level being fixed so that for average normal ears the last two tone and noise levels of the test would not be heard.

STIMULI Four tests were used in this study. A recorded speech reception test, The Harvard Auditory Test #14> was used to determine speech-reception thresholds.1 (Appendix B) "^Available through the research department of the Central Institute for the Deaf, St. Louis 10, Missouri. 29

The second was a recording of four pure tones, 500, 1,000, 2,000, and 4>000 c.p.s. They were recorded at a fixed level using a pure-tone audiometer as the sound source. The third test was a multiple-tone pulse-type, a recorded test complete unto itself including instructions and test tones for the frequencies 500, 1,000, 2,000, and 4,000 c.p.s. (Appendix C). The fourth recorded test was the single-tone pulse-type and the white-noise pulse-type test consisting of six forms, each form comprising a complete test. It consisted of a series of 500 cycle-tone pulses and a series of bursts of white noise. The intensity levels of the multiple-tone pulse-type and the single-tone pulse-type and white-noise pulse-type test were determined by 10 normal hearing individuals who matched in loudness the test tones of the two tests with the corresponding pure tones from an audiometer set at an intensity level of 15 db. The level of the single-tone pulse-type and white-noise pulse-type test was set so that the last two series of tone and noise (columns 9 and 10) would not be heard by average normal ears.

SUBJECTS The subjects used in this study were 119 male college students, predominately freshmen of five colleges at The Ohio State University. They were selected as subjects on the basis of having failed to make a perfect score on the multiple-tone pulse-type test when it was administered as I

3° part of the physical examination during the Orientation Week in September, 1951. The 119 subjects were selected from a total of 247 students who failed the test. One hundred twenty-eight of the 247 students could not be contacted or were unable to participate in the experiment.

PRESENTATION The tests were administed individually. Each subject was seated in a sound-treated room. The ,rVoice-of-the- Theater".(Altec-Lansing Co.) loudspeaker was six feet in front of the subject. To his right was a microphone used for communication with the control room. Two pairs of high- fidelity earphones were on a table beside the subject. A clipboard with the test forms for the multiple-tone pulse- type test and the single-tone pulse-type and white-noise pulse-type test was held by the subject. A window, directly behind the subject, was between the sound-treated room and the control room so that the experimenter could see the subject at all times. Each of the four tests was explained to the subject immediately before presentation. The subject recorded results of the single-tone pulse-type and the white-noise pulse-type test and the multiple-tone pulse-type test. The experimenter recorded the scores for the pure-tone and speech-reception tests. The order in which the tests were presented is shown in Table I. This order was repeated for each group of 10 subjects. The tests were administered as follows: r

Multiple-tone pulse-type test: The subject wore a pair of high-fidelity earphones. He received the entire test (Appendix C) through the earphones. He recorded his scores on the form provided him (Appendix D). The experi­ menter controlled the test level as previously determined and also controlled the order of ears tested. Only one ear­ phone functioned at any given time. The retest was the same presentation as the first test. It was administered at a level 10 db lower in intensity than the first test. The subject was told only that the retest would be the same form as the original test. Single-tone pulse-type and white-noise pulse-type test: This test was administered binaurally and monaurally. The first test was binaural. The subject wore a pair of calibrated high-fidelity earphones. Instructions as to the type of stimuli he would hear and how he was to score the test form (Appendix E) were given orally. The test was played by recording at a predetermined level. The subject heard from two to four pulses of a 500-cycle tone for each column of the score sheet. The second row of the test form was for recording responses to bursts of white noise which the subject heard. The 500-cycle tone and the bursts of white noise were attenuated on the record in two-decibel steps for each column of the test. Immediately following the first test an identical test was given with the exception of numbers of tones and 32

■bursts of white noise for each column. The monaural test was then given. The subject wore a pair of high-fidelity earphones only one of. which functioned at a time. The test was identical to the binaural test with the exception of numbers of tones and bursts of noise heard. The ear tested first depended upon the test order. Pure-tone test: The subject wore a pair of high- fidelity earphones. Recorded tones were presented in the following order: 500 c.p.s., 1,000 c.p.s., 2,000 c.p.s., and 4,000 c. p.s. The ear tested first depended upon the order of the test as determined by the experimenter. The subject was asked to indicate if he heard by raising his hand each time he heard a tone. The tones could be attenuated in one-decibel steps. In this manner thresholds for the four tones for each ear were determined and recorded by the examiner. Speech-reception test: This test was administered in a free-field condition. The Harvard Auditory Test #14 (Appendix B) was used. The subject was instructed to repeat each word, he heard. The experimenter, by attenuating the intensity of the signal in one-decibel steps, was able to determine the speech reception threshold. The level was recorded by the experimenter. Multiple choice word intelligibility test: This test was given as part of the series of tests but is not evaluated in this study. 33

SCORING OF TESTS Scores for each, test were: Speech reception test: One score, the db level at which 50% of correct responses were given. Pure-tone test: Eight scores, the db level relative to threshold for each of four tones for each ear. Single-tone pulse-type and white-noise pulse-type test: Eight scores, the total number of columns correct for each test of pure tone and noise. Multiple-tone pulse-type test: Two scores, one for each ear as recorded by the subject.

The scores were accumulated into a group composite score sheet which gave the score for each item of each test. These tables served as the source of scores for the statis­ tical analyses. CHAPTER IV RESULTS AND DISCUSSION PART I

On© hundred nineteen male college students served as experimental subjects in an evaluation of two hearing tests. The experimental subjects were selected on the basis of having failed to make a perfect score on a multi­ ple-tone pulse-type test that was administered as part of the physical examination during The Ohio State University Orientation Week in September, 1951. The batter of four tests yielded a total of 23 scores for each subject. The responses of the listeners (subjects) to two of the tests (pure-tone and speech-reception) comprised the criterion measures of the analyses. Table II enumerates the analyses that were made and implies the statistical methods that were used.

Hypothesis I Scores of the pure-tone test, when categorized on the basis of perfect and imperfect scores, are unrelated to the speech-reception scores as categorized into higher half and lower half of scores. The hypothesis was tested in the following manner;

34 F

35

Scores of the pure-tone test were categorized on the * basis of perfect and imperfect scores. The original plan * The signal noise ratio of the record .used in this test was.50 db. In only one instance in calibrating the equipment to correct loudness level was it found that a person heard the signals at the lower limit of the equip­ ment. In this instance all four frequencies tested were also heard at -10 db level on a Maico Model D-9 pure-tone audiometer. Thus there was no indication prior to making the original measurements of the study that many of the subjects would secure perfect scores. This could have been avoided within the limits of the. equipment.

called for analyses of variance between means of the speech- reception scores and scores of the pure-tone test. This was not feasible since many of the scores for the pure-tone test reached the lower limit of the equipment used in obtaining the scores and were not adequately distributed for this type of analyses. Those scores that reached the lower limit of the testing equipment were designated as perfect scores. Imperfect scores were all those above the lower limit. The pure-tone scores were so arranged for each of the four fre­ quencies tested for each ear. The speech-reception scores were categorized into higher half of scores and lower half of scores. The division was made as near the median as was feasible. The Chi-square test of independence was made to determine the relationship of the two tests. The example below demonstrates the arrangement of scores in a contin­ gency table. TABLE II TESTS STATISTICS Tests of (a) independence and (t>) corre­ (a) Chi-Square lation between scores of the pure-tone (b) Bi-serial test and the speech-reception test correlation (binaural). A comparison of the means of groups of listeners scores for the multiple-tone F-ratio pulse-type test and the pure-tone test. A comparison of (a) mean scores and (b) correlation between scores of the speech (a) F-ratio reception test and the multiple-tone (b) Bi-serial pulse-type test. correlation Tests of (a) independence and (b) corre­ lation between scores of the original (a) Chi-square multiple-tone pulse-type test as given (b) Tetrachoric in September, 1951 > and the same test correlation under laboratory conditions. Tests of (a) independence and (b) corre­ (a) Chi-square lation between scores of tha multiple- (b) Tetrachoric tone pulse-type test and retest under correlation laboratory conditions. A comparison of the means of groups of listeners scores for the single-tone F-ratio pulse-type, the white-noise pulse-type test (monaural) and the pure-tone test. A comparison of the means of groups of listeners scores for the single-tone F-ratio pulse-type, the white-noise pulse-type test (binaural) and scores of the pure- tone test. Tests of (a) independence and (b) corre­ lation between scores of the single-tone (a) Chi-square pulse-type, and white-noise pulse-type (b) Bi-serial (binaural) and the speech reception tests. correlation Tests of (a) independence and (b) corre­ lation between scores of the single-tone (a) Chi-square pulse-type, the white-noise pulse-type (b) Bi-serial tests (binaural retests) and the speech correlation - reception test. 37 Pure-Tone Scores Perfect Imperfect Higher Half 52 13 65 Speech-Recep- (42.05) (22.95) tion Scores 25 29 54 Lower Half (34.95) (19.05) 77 42 119 2 (52-42.05) (13-22.95) (25-34.95) (29-19.05)2 = i 4.68 42.05 22.95 19.05 19.05 The number of scores for each of the categories for each analysis was: Speech Reception Pure Tone Higher Lower Perfect Imperfect Half : Half Leift Ear 500 c.p.s. 77 42 65 54 1,000 c.p.s. 15 104 65 54 2,000 c.p.s. 56 63 65 54 4,000 c.p.s. 22 97 65 54 Right Ear 500 c.p.s. 71 48 65 54 1,000 c.p.s. 11 108 65 54 2,000 c.p.s. 54 65 65 54 4,000 c.p.s. 27 92 65 54

Results of the Chi-square tests of independence are summar­ ized in Table III. For the 500 c.p.s. frequency for each ear and the speech-reception scores, significance at the one per cent level of confidence was obtained. The levels of confidence obtained for the 1,000 c.p.s. frequency was between the 10 and 15 per cent and the 5 and 10 per cent levels for the left and right ears respectively. For the 2,000 c.p.s. frequency the relationship for the left ear was significant at the one per cent level of confidence and for the right ear, between the one and two per cent level. TABLE III SUMMARY OF TESTS OF INDEPENDENCE AND CORRELATION OF PURE-TONE SCORES AND SPEECH-RECEPTION SCORES.

Bi-serial Correlation Chi-Square Ear Frequency Ear Frequency-

Left 500 c.p.s. • h-7 *****Left 500 c.p.s. 14. 68* 1,000 c.p.s. .25sfc 1,000 c.p.s. 2.43^ 2,000 c.p.s. •^°* 2,000 c.p.s. 9.66 4,000 c.p.s. .28 4,000 c.p.s. 5.5S

Right 500 c.p.s. .49* Right 500 c.p.s. 14*70 1,000 c.p.s. •30* 1,000 c.p.s. 3.63 2,000 c.p.s. •39* 2,000 c.p.s. 5.77 4,000 c.p.s. .32* 4,000 c.p.s. 7.54”

Under an assumption that r is equal to r ^ : * Significant at the 1$ level of confidence. ** Significant at the 10-15$ level of confidence, *** Significant at the 5-10$ level of confidence. **** significant at the 1 -2$ level of confidence. ***** Significant at the 5$ level of confidence.

The 4*000 c.p.s. frequency- was significant at the five per cent level of confidence for the left ear and at the one per cent level for the right ears. Generally speaking,

these results agree with those of Beasley. 1 He concluded I Willis C. Beasley, "Correlation Between Hearing Loss Measurements by Air Conduction on Eight Tones," J ournal of the Acoustical Society of America. 12:104, 1940.

that the four frequencies, 500, 1 ,0 00, 2 ,000, and 4*000 c.p.s. provide approximately equal prediotive value for hearing 39 acuity throughout the range. He further concluded that either the 1,000 c.p.s. tone or the 2,000 c.p.s. tone is about equally predictive of the ability to hear speech, but that a tone in the region of 2,000 c.p.s. is preferable. While exactly the same results were not shown in the tests summarized here, the 2,000 c.p.s. frequency is statistically highly significant in relation to the speech reception scores. Also shown in Table III are results of the Bi-serial correlations for each of the frequencies for each ear of the pure-tone tests and scores of the speech-reception tests. The reasons for using the Bi-serial correlation for the analyses instead of the Contingency Coefficient which is often associated with Chi-square was that the data included one set of scores that was normally distributed: the speech reception thresholds. Thus it seemed that Bi-serial correla­ tion fitted the data more efficiently than would the Contin­ gency Coefficient. Peatman states: The Bi-serial correlation is used for situations in which one of the bi-variates is dichotomized rather than continuously distributed and is based on the assumption that the variable which is dichotomized would, if quantitatively differentiated, yield the normal, bell-type distribution. The continuously distributed variable that is correlated with the dichotomized one is not, however, assumed to be normally distributed.2 2 J. G. Peatman, Descriptive and Sampling Statistics, Hew York: Harper and Brothers, 194-7, P- 259. 40

The scores for these analyses were dichotomized into •perfect-imperfect classifications with respect to the sub­ jects’ responses to each frequency: 500, 1,000, 2,000, 4.000 c.p.s. (and for each ear). The speech-reception scores (db attenuation accompanying threshold) were arrayed in columns under each dichotomy. Values of the Bi-serial corre­ lations between pure-tone threshold and speech-reception threshold ranged from .49 (500 c.p.s. tone, right ears) to .28 (4,000 c.p.s. tone, left ears). The eight correlation values are enumerated in Table III. In the instance of the 500 c.p.s. tone for the left ears a correlation of .47 was obtained; the 1,000 c.p.s. tones, left and right ears, .25 and .30 respectively; the 2,000 c.p.s. tone, .40 and .39, left and right ears respectively; the 4,000 c.p.s. tone, .28 for the left ears and .32 for the right ears. Under the assumption that r is equal to r^., all of the correla­ tions between pure-tone thresholds and speech-reception thresholds were significant at the one per cent level of confidence with the exception of the value associated with 1.000 c.p.s. and the left ears which was significant at the five per cent level. Therefore, the hypothesis of no relationship between the scores of the pure-tone test and the speech-reception test was rejected. Scores for one of the tests correlate significantly with scores of the other test. Hypothesis II The second hypothesis under test was, "there is no difference between means of the groups when the subjects were grouped according to scores of the multiple-tone pulse- type test for a given frequency for a particular ear." Six columns of scores were arranged according to the scores of single ears on the multiple-tone pulse-type test, namely 5, 4, 3, 2, 1, 0. Five is a perfect score, the ear having received all tones presented, and scores below five represent progressively poorer scores. The subjects scores on the pure-tone test were entered in the columns as basic measures. Tabulations were made for eight sets of scores representing each of the four frequencies of the pure-tone scores for the left and right ears. The number of scores for the 5, 4, 3, 2, 1, 0, columns were 74, 29, 4, 5, 4, and 3 for the left ears and SO, 25, 3, 4, 2, and 5 for the right ears respectively. The form below illustrates the arrange­ ment of scores for the analyses. Scores Yielded to Subjects by the Multiple-Tone Pulse-Type Test 4 3 2 1 0

(Subjects scores on the pure-tone test were entered as basic measures.) 42

Results of eight analyses of variance are shown in Table IV. The F-ration (for unequal columns) for the tests was statistically highly significant at the one per cent level of confidence for both left and right ears. Results indicate a progressive increase in the F-ratio associated with the scores on the multiple-tone pulse-type test for the left ear as the frequency of the pure-tone test increased from 500 c.p.s. through 4 ,000 c.p.s. However, similar results were not obtained in connection with the right ears, that is, the general pattern shown by scores for the left ears was not duplicated. The mean values for each frequency of the pure-tone test are shown in Table V. It is noted that for the left ears the mean threshold scores for the pure-tone tests increased with corresponding lower scores on the multiple- tone pulse-type tests with the exception of the zero scores on the multiple-tone pulse-type tests. These results were obtained for all four frequencies of the pure-tone test. Possibly either or both of two factors accounted for the reduced values associated with the zero scores: (l) the small number of scores in the 3, 2, 1, 0, categories of the multiple-tone pulse-type test and therefore the relatively low reliability of these scores and (2) factors other than a hearing loss were contributing to the zero scores. """the PURE-TONE*TEST AND THE MULTIPLE-TONE PULSE-TYPi TEST "(Monaurel) Sources of Degrees of Sums of Ear Frequency Variation Freedom Squares Variance F Left 500 c.p.s. Levels of Scores 5 4,335.57 967 .ll 18.45** Within Columns 5.923.72 52.42 Total SI. 10,759.29 1,000 c.p.s. Levels of Scores 12,228.44 2,445.69 22.84** Within Columns 12,101.50 107.09 Total SI 24,329.94 2,000 c.p.s. Levels of Scores 5 24,913.91 4,982.78 25.14** Within Columns 111 22,395.59 198.19 Total 118 47,309.50 4,000 c.p.s. Levels of Scores 5 36,254.93 7,250.99 29.32** Within Columns 111 27x947.* 3.6 247.32 Total 118 64,202.29 Right 500 c.p.s. Levels of Scores 10 ,192.13 2,038.43 33.26** Within Columns 6,925.84 61.29 Total 4 17,117.97 1,000 c.p.s. Levels of Scores 16,522.00 3,304.40 29.04** Within Columns 12.855.75 113.77 Total ill 29.377.75 2,000 c.p.s. Levels of Scores 5 27,228.75 5,445.75 25.92** Within Columns 23,741.12 210.10 Total 118 50,969.87 4,000 c.p.s. Levels of Scores 5 47,916.37 9,583.27 39.44** Within Columns 27,456.50 242.98 Total m 75,372.87 **Significant (F) at the Vfo level of confidence. -p- TABLE Y

MEAN SCORES IN DECIBELS FOR THE PURE-TONE TESTS FOR SIX LEVELS OF SCORES FOR THE MOLTIPLE-TONE PULSE-TYPE TEST.

1 s r Levels of Scores- Multiple-Tone Pulse-Type Test Ear Frequency 5 4 3 2 0

Left 500 c.p.s. 4.00 6.03 10.30, 20.00 29.00 28.00 1,000 c.p.s. 22.09 22.69 36.75 42.60 71.50 42.00 2,000 c.p.s. 9.85 14.79 45.50 45.80 69.50 46.33 4,000 c.p.s. 24.26 49.79 58.00 76.20 81.50 63.67

Right 500 c.p.s. 4.54 9.00 4.00 18.75 16.00 49.40 1,000 c.p.s. 23.86 23.24 47.00 48.00 6.35 71.40 2,000 c.p.s. 10.69 18.04 43.33 3.05 64.50 74.80 4,000 c.p.s. 22.26 54.12 86.33 60.00 85.50 80.40

Comparison of' Pairs of Means in Successive Rows of Columns Headed £ and k * Left Ear Right Ear

500 c.p.s. » t 1.39 4.85* 1,000 c.p.s. .26 .48 2,000 c. p. s.1 £ 2.86* 4.40* 4,000 c.p.s. > £ 7.38* 16.26*

*Significant at tlie 1 fo level of confidence.

•p- ■p- 45

Mean scores for the right ears for the 500 c.p.s. tone were similar in magnitude to those of the left ear. However, mean scores for the 1,000, 2,000, 4,000-cycle frequencies revealed sharp fluctuations in the one, two, and two multi- ple-tone pulse-type test scores respectively from the patterns of the left ears. Possibly the same factors account for these scores as for the zero scores for the left ears. Table V also includes results of tj-tests that were made to test the significance of the differences between pairs of means. Because of the relatively small differences between pairs of means of the 5 and 4 categories of the multiple-tone pulse-type test, t_-tests for comparisons of pairs of means for these two columns were made. The 5 and 4 categories of the multiple-tone pulse-type test associated with the 500 c.p.s. tone and the 1,000 c.p.s. tone for the left ears were not significant while these same categories for the 2,000 c.p.s. and 4,000 c.p.s. tones were significant at the one per cent level of confidence. The difference in means for the 4,000 c.p.s. tone was greater than the differ­ ence for the other frequencies, indicating that the 5 and 4 scores of the multiple-tone test were discriminating a loss of hearing at 4,000 c.p.s. The same results were obtained for the right ear with the exception that the difference in means for the 500 c.p.s. tone was significant at the one per cent level of confidence. 46

Because of the small number of scores in the 3, 2, 1, and 0 categories of the multiple-tone pulse-type test, the scores for like categories for the left and right ears of the multiple-tone pulse-type test were pooled. Table VI enumerates the mean scores for the pooled categories. The mean values of these analyses are plotted in three sets of figures. Measurements associated with right and left ears are plotted in Figures 1 and 2, and as pooled, in Figure 3« Even in this latter grouping there were few measures under the headings of 3, 2, 1, and 0, only 7, 9, 6, and 8 respec­ tively. Hence these cases were pooled and assigned a weighted 0-3 value, specifically 1.5* The grouped data are represented by the plots in Figure 4- In summary, the analyses of variance showed a high degree of relationship between scores of the pure-tone test and the multiple-tone pulse-type test. This was particularly true for the 3, 2, 1, and 0 categories of the multiple-tone pulse-type test. There was a significant difference between the means of the 5 and 4 categories of the multiple-tone pulse-type test and the 4,000 c.p.s. frequency of the pure- tone test. Factors other than a hearing loss seemed to affect the pure-tone thresholds associated with the zero category of the multiple-tone pulse-type test. 47

TABLE VI MEAN THRESHOLD VALUES (RELATIVE DB) OB PURE TONES ASSOCIATED. WITH EARS THAT ARE CATEGORIZED 5-0 ON THE MULTIPLE-TONE TEST.

Category of Scores for Multiple-Tone Test Frequency 5 4 3 2 1 0 500 c.p.s. 4.28 7.59 7.57 19.44 24.66 44.75 1.000 c.p.s. 23.01 22.94 41.14 45.00 68.83 60.38 2.000 c.p.s. 10.29 16.30 44.57 39.00 67.83 64.13 4.000 c.p.s. 23.22 51.80 70.14 69.00 82.83 74-13

Hypothesis III The third hypothesis under test was, "with subjects grouped according to three categories of the multiple-tone pulse-type test, there is no difference between the means of the groups as measured by scores of the speech-reception test." Scores of the speech-reception test were arranged in columns designated as Perfect-Perfect (scores of 5 for both ears), Perfect-Imperfect (score of 5 for one ear), and Imperfect-Imperfect (score of 5 for neither ear). This classification was on the basis of scores for the multiple- tone pulse-type test. There were two reasons for this classification: (l) since the speech reception test was a binaural test it was felt that scores for each ear of the multiple-tone pulse type-test should be treated as binaural scores; and (2) the number of scores in some of Mean Scores in Relative db Level-Left Ear-500,1000,2000,4000 c.p.s T 7-.-.:r: V " CA ’..0^ ' -4 ' " 03 " ■ " ‘ N>.. • • O . CO . .. Ov. ' tO .. :. O 03 O £~ \.k- r^*-r -& \rr ------, - ' ' -- Kt*l" -■c+ : O :i " £1. CHWUirViO <+ O ' f c : ’ . a 4 c+ h* 4 - i n ­ to. -.'H.-O'M-W.; • to to to ‘ *3 1 o a--:---!' " B r t o i • - , o tf-t+to* . - t o ' .. .i.to-O-': | j i ^ \ra • • < D - to! tro c+ 4T ■0 ■: •irfto '• : ■ .+j_. f2 OQ ■ o a a - ' - to H O fcj fcrj ; to t o 4 - , .. >31? COCO I • ). * K ! ^ - - y^Ji - - Sr- \js- , , 9 *4 •• -to_ .*3 IIS-© 3 - - - to - to - c+ fOH ■CQ -O !Q ■•70 ; • ; S ^ : - *i ■ ' " ■ t o r - : - - to .r • • +164W. - *4 *4 - >d I ! .... . O ^ ’n -■ ■■ to to ■ : / : f y ||:0 35. -". - V1 ■ ■® - ...... c * - c + -« + • - c r - • c + - - p-.-O- 0 - 0 5 to EJ ! • • 1 EO-OW ; ' |W to' -to to .. >5 . r.-. ■ r | .. -

rP« < *11 TO *’00 71 MTIJL 'D 0*3-1 r r - t i..- lr. ■ v v & f l L • ' •V • W K : ■ v : : - i . O L f h '■ 3S:0>!. : • H ? t o.-p' 022 . ' ■ ■ ■ ■ !t":; i' '" :: V . ,_fc! ;•• : a g K s . w : was. iffel;: + 3 t 3 T O i T O ’ - ; * y . ^ :fO O .: O M ••• raw.; i 513 ta/i-.w r f *4-: -r .. t - ' - r s :• : a . .. ..• ■- -

. -•-:<+"•IP*:' v;o ■ :-j • . ; ip-.::; . V> . : . v(D V.T- I.', /I ■ I - VJ . its:: itr-V:; ■■ 1 "-':'. ® m 'il'-v*- *t *d' "i •; ' P *3 Tv W 4v 4v = H v H - v H- w - v c+ ' 'O - b ' W • a .•-• O ' CQ 0 3 I : . •' .. ro- ......

• 1 ■ . . v . r ' :---.

---- -P^ .. _ Mean Scoresin Relativedb Level-Right Ear-500,1000,2000,4000c.p.s. -v.r . . .. -

^!Tfev!-;!|T;rTTT:-: : v v . v v - v : ; r7:T77-7.:. £ ; :K)*coW': ;■ ; :r- vrT7|:fT:7:7T-17^.p::.- & « ^ £3 ' T ” t r e f T r :Tf”7 ; O ...' t . O r O ‘ V ' .f ho- .-fr O'- CV ‘ O ro ;.JO .W..'. to . :.. -O' ; j v ; . : j“v;i v v ■ : •; j v.;;. ; .vrr:7r-^vrj7.;5Fv; 7“:7 : “ 7 ^ 7 ; v F 5 ; . 7 j r v ^ - r 7 : r r v . • . 7 - 7 \ v : : . • . : .. fev! v e f f c ... :: : ;. • .. i : v . T : . : v \ 7 v : v T v . . i : | ; J v ; T ! -~ : i “!v ^ ~ ‘ r v : v : ' " " ‘ ~ “T r r r - : v : y / ' r v r : : ; ‘ ^0’ : ^ r r r g * . ' d g h : : v • T -1 ; r ■ | :-fi vT; ■ ij ^ v ^ ;.r ; Vp ■ i-y1 -' •/• • • © S - - ® • • : • • • / • ' - i 1 ’ y - i • ■ p V ; • : T ^ . ^ ..v _ t t J&X+.-T - . + X & J : v . H ■■P'xn'O; v H O •: O - H v : . - . V • ! vvv : .! « . P : v v v • "j :r:T':Ti©7i^ i _ _ ^ q c "i T r -uT::j®±^-LJL© „i . ; • - . ; c t i d -; c t . i a : - : | t I —r i - f ■ - ■ ; • . ■' B 4 - « •j« ■'* . • -■ j «• « -• W . v . ..’ : ;.v T 7 o * ;jQ7©:!:OQv| i . v f f ffl . ® • ; , . v : : ; J -•: : 4- :c*H*:4.:i i : . 4 : * H * c : - 4 . a r p v v i T 7 ■ :;d-0 f ■I ’ ' ■ I* i rB.a :! dO O ‘d -tHvi f O v • dV : --I v.rj v:T! -r] ■ * : Mean Scores in Relative db Level-Both Ears-500.1000,2000,4000 c.p.s. [■? »■*- » ' • ' • ■JrJ- r- f : ■? ' I I-j.'vx l *: :— ~dvattrrr:- •:-rr^~rr-rjo^.^~-~^rrrr^-T^/\yrT•— :—. : ■'r—vr! ;--- : £- • K) ' • cr- ” w o. " i --.T V . ::v: .:-?

r&er 2

f3 .. i’tet" ;':CQt9d :■■■«■■& § § § £ ;,-OiO-.4 H'0 ■ ' t fcrl M:, t P;-a jS " H3. , • M : ...gtmfc.: .■-! . Moos;. ;K. f -td.^a-pr - S&.S...

]■ ■; M-O M...... 2 :P;.' — r i-'-f-. ••O" -Or-p-" ur'ii > -:». W . ipj:--- :4 ' - i r~ p' P . - p -; p . j . .-.c d i .- m . I— C3 - jOe»j W ' rut rin i1 jraru.*p-P l«X ;*b r'-:O . - l b - - W ■ - ■ "■■ * -. ;\Vjr:-'-:-.4 fcTi*CJ; . { ..; . “p«r.•:: 'la VitB : ."; UPBL rprrrh \ r hr.-:; ....< : . \f ; r ; j

fa r :r‘■ J: c* *+"' c*’j Pirprrc-V. t jr -. f.p j ;:.; .1 - ,:p ;p .. p t . I B . : i j p .- P ‘ I

...... MCQ . -I - i 141 —r,M i £i ■ H^rr" .;_/' r • ', iifi..; 4 r';.;1/.i" : - q -j,-1' ': - ! Mean Scores in Relative db Level-Both Ears-500,1000,2000,4000 c.p.s,

■ ^ 4 4

■ *■3 r .to; o to o e+ 1-P-vjiO - H ; 4 :h* J : © " o -cf- -Scrr

rH- t?S5

.H " OO'Z -Q ■■■.-■• © ■ J-Hfd 5tTt3' ,G to i- -H ■-■'■: It + 3 O ‘ - :0 hj-o ^2I ' : : 0 ' W 4 - S-W--V37-Ot-'-i— i .« *d;!> O ; ~ " "'-i to----- " • 4 Q

i - 3 4 Hto.H ft VjJ

*QW-i- “

"PIP::-CO-;.: •• , IO AJ * ? 4 4 ___ 4 4 : 4 -. s3'<> . \h : 52 the categories of the multiple-tone pulse-type test was too small to be treated in an analysis of variance. The follow­ ing example shows how the scores were arranged. Perfect-Perfect Perfect-Imperfect Imperfect-Imperfect 16 22 14

(Enter subjects1 scores on the speech reception test as basic measures.)

The number of scores for each of the three categories, Perfect-Perfect, Perfect-Imperfect and Imperfect-Imperfect respectively was 6 5 , 2 4 , and 30. An analysis of variance was used to test for differences among the mean scores. The results are summarized in Table VII. The F-ratio was significant at the one per cent level of confidence. Mean scores for the tests are shown in Table VIII.

TABLE VII SUMMARY OF AW ANALYSES OF VARIANCE: MEASURES OF SCORES FOR THE SPEECH-RECEPTION TEST AND THE MULTIPLE-TONE PULSE-TYPE TEST

Sources of Degrees of Sums of Variation Freedom Squares Variance F

Levels of Scores 2 312.98 156.49 4 . 8 4 * * Within Columns 116 3.748.87 32.32 Total 118 4,061.85 **Significant (F) at the 1 fo level of confidence. TABLE VIII MEAN SCORES EOR THE SPEECH-RECEPTION TESTS IN THREE LEVELS OE THE MOLTIPLE-TONE PULSE-TYPE TEST

Multipie-Tone Pulse-Type Test Perfect- Perfect- Imperfect- ______Perfect____ Imperfect____ Imperfect Mean Score Speech-Reception 18.58 19.38 22.47 Test

Comparisons of Pairs of Means of Columbus headed Perfect-Perfect, Perfect-Imperfect, and Imperfect- Imperfect. Columns Perfect-Perfect and Perfect-Imperfect, t_ *81 Perfect-Imperfect and Imperfect-Imperfect, t 1.59*1. Perfect-Perfect and Imperfect-Imperfect, t 2.97

**Significant at the 1$ level of confidence. ^Significant near the 10$ level of confidence.

Table VIII also shows results of the t-test'for significance of differences between means of the three categories. The difference between the Perfect-Perfect and Imperfect-Imperfect categories was significant at the one per cent level of confidence. Mean scores for the three categories are also por­ trayed graphically in Figure 5» This illustrates a pro- gressibly lower scores for the speech-reception tests in the three categories of the multiple-tone pulse-type test ranging from the Perfect-Perfect category through the Imperfect-Imperfect category. r 54 F. ).■’:Tr“ n ^ F F T F: • ; f i -j i | • L • » -I : . ; 1 »• I ‘ : :yi :.zl; : i'i M” I j i • ; *4 «■ > ; '* 1 1 1 ' * I - rj-T. :n : ; . [ f 7; 'I y i y M M-.-M’ ; S U a M .•!; [' HI;.;; _v;|;: I d i; i p ;, j y :| i: 7 -;u;yv.r:-;it;v• • :r - t ] 7 1 7 iM F: y:-ijF:i: y;r y 7 Fj ; J r | ; j ^ i i;i_ _**^. y I..I 7 7 y r 7 7 , | ' . ? j >M i ! ■" r i 1' ■4' i-" pf;: j i ’,. y ' I M ■ \ i * i ■ 4

• M i ' T''M^)yT'FFujyMi^iF^ifiy^FriF:;-t'-n TM rrr-yi f? ; M • { M t..: j , -I y.M ■ j i i.-f; ■ iv ■ MMFM--jv: - IMV : I ' . < 1 y;yt i , ; ' i | ■ J . ' V. - •. u .1 i r .. . :.y y..:. .yj.r.'v j.,... . . pyy i: .. .p :_y ;-i„y J . I r: F_.• i :: '' f . i \:r . 1 " •:77 1 7 :r: y MTFFfF;'-j:7 7 ]' • I L * . - . , ...... I . i. . .. I .. * f , _ I ■ . '.'j.I _ . T : 4: ,•'i• J ‘ ' 4..ut{, 1 I ri: ; r t^ r 'r;': -T t: r"j-p

- i n - y i ' F -i-y'■•■"IM ;{"?;ri:7 ;;| : I j ;0- i-: r ; *H :• ■ • . **! “:;M r ; ; ■ , | ' J - L ^ j ' j- ■ ' F ■ | *" ! .. PU 4 ‘ : c. i ■ :■ ; O :, i -.L • .: .1 ;; ;i! j F : ; iF :. i' ;:r.<: 7:F ••• 03 ■ r- F'tt yMriiFHM I •' -! : w ; i-‘ i i -! : t l ; t j ;-:1 ■ ;i^ n !>; i ' • i • , . I - ■ "t".■ 1 * i • ; r- r ; t ; • • • • 1- 1 5 •• * • i . • Fa ’ I ;1 ;.!A: .; rr.: . I ...' i F.U^-P-P-. pi-bp. I ■ : i i:;:' I m 2 4 ' - ' - ! ■ ■■ Mir : F : ! f M ; I ; | , • f ; • ‘ 1 ; li ;.. •. I'i.p ;T i ;'' '• " : ■ ] ! ' j-i - ; • ; ■ r : ; : ; r '• 1.r J J . . It- i: ■ ■ 1 ri:f-TPTi^:• I . ■•>-. ~ -•1 ^;MrH"n‘yF^r^piyyr,ip'!yib'^;r- : , J 4 -L ■! j ! - I I ...... i . 'r ■' -4 ' vri T ■ ' ’i ■; ;y : ' +? M i J. ' p ' , ;. :•:;■;■■■

; ^ .20 ..pN. = . ' 2 4 IF cJ:-:. . t.i.i .. :! / : - t. i-; •fHfl;-, p iMjlM • -» • i .• • i • Itvr.-rb.!::<- ■ I—

W ’" t.P- , FFI ii-Fi-i- !' H :-t-:j»i-. m m w ?T ...... : ii'f y Frlly il-^ 7 tyrr FiiFMl'id m ifi' f'MiM SI.;:..' MmM ■■■': ■' t r! ■■ >'-■ I i l l i j'^;r I yt; I-:.-!;: M y y j Imperfect- ;I:. - T J . ^ 1, 1 • ■ I I ••! ! Iiphti::!:tr;iT! Hi- rv;I';r:'i;:i m p a r f e c t Mr- yj|M;H pi'-liLUyl-.-U.iiM;'.brjiy y b F.jl■''■ r.FiliF >' M liJ id ! i.J

7 - r ' ' M r Li:i : ■ •'; • : I Mr! M Fy" i ' fp" ' iyM iM F--i.:;- F n r :-7-b'! 7 - : v; p -itr '-1 f'f ; F y ;-! ■ : '-j . : ; : P M ■iy-UyFyiMyiFlMilLlMiM^ LMyM.y ,7 .M^ piJA’.yUTf.yMjM1

! 'i f . . A :cmAtferCAli,..RSPSESiBI'iTATli:Q lk ' .03?.jTaa* ■ BB llA r ! ; : .I '? : ' ! : : i :,.TIOIjlSHIP K 5T O E K T S 2I UffiAN-• SC D R S g 1:’OT , THE p " M'y y - y ; rf. 7|:rMM7^ i i £ e a “^SCJjS?T2 ON :; p., : i ; j ' :J: 7 . . y X Q t o O N S . . OF. • SC O R E 'S ; y ,M [7■;;!!J!■[.;I i ;.;':^ T IF U S -T O N F Ft?BlOE-r|rifFE;:^ S T . pry.,, :;.; t: v -l-n y -:-; .-u ~ y'Sy-n; - - :• - s-; •; .v p tr r : F -r-yy-F -. -j-.-:— P-‘ y- -r-v- : 7 ''i7’7 My';-:'-p-rrj ...... -f*;?-jl;i*.T!-r;ii].-i!p:i:M,iMi'1- : :-!‘: -i■ ^!' ■ ' - -M4-?*iii'ciMmL:rri;j‘i. 7 M i;M ir M ;, FiM; i7 7 ; •'.- ;i ■-]:; p p-r- -t‘ ;;:y- > p y . vvp.yr/ --t, .y-;-iy r:: y;-;: :•;■ yp ■; lprq:\ tT‘- I r r:,: -iM iFFpl'F.y !:- ! • ■ ■ ! iJy-H

yuFyHiF'Kyj.yyypy'-y: yy-y! ■■: -ypyppyyyy i .p p f ■ yyif'FyfppFyM PMiiib ’ ■!-!•■: ;■; :•■. ■ : I i : i ‘: :i:: -y by’:-; • ;-pyr;!yyr;;p;yyH7--7-PbF i F •; * i.F'F.;! 7 F r: iiiy-iF . ;H L- . >i ■ l:.l. 4-i-p ; . ! . ;-r-r! . | y ...] , 4 y ' y Kv. T-2»t« «. TJJ.K )i COt.r

TJb.e Bi-serial correlation was used for a second analysis of the tests. Scores of the multiple-tone pulse- type test were arranged into a Perfect-Imperfect category. Five was classified as a perfect score for this category and all others, l+> 3, 2, 1, and 0, imperfect scores. These scores were compared with scores of the speech-reception test. In the analysis the retest of the multiple-tone pulse-type test was also compared with scores of the speech- reception test. Table IX shows the results of the tests for both ears.

TABLE IX BI-SERIAL CORRELATIONS, EOR MEASUREMENTS OF BINAURAL SPEECH-RECEPTION SCORES AND THE MULTIPLE-TONE PULSE- . T3JPE TEST UNDER TWO LABORATORY CONDITIONS

Bi-Serial Correlation Right Ear Left Ear Multiple-Tone Pulse-Type Test #1 and Speech .53* • 47* Reception Test Multiple-Tone Pulse-Type Test ff2 (retest, 1 minus .2 S* .40* 10 db) and Speech Reception Test

^Significant at the 1 fa level of confidence.

Under the assumption that r is equal to r , there bi was significant correlation at the one per cent level of confidence between the multiple-tone pulse-type test and retest and the speech reception scores for both ears. 56

It Is noted that the correlation between the speech-reception tests and the retest of the multiple-tone pulse-type test is lower than for the first test of the multiple-tone pulse- type test. A possible explanation for this is that the retest was given at a level 10 db lower than the first test. Mean scores for each category of the speech-reception test and the two multiple-tone pulse-type tests are shown in Table X.

TABLE X MEAN SCORES OF THE MULTIPLE-TONE PULSE-TYPE TEST AND RETEST IN TWO CATEGORIES OF SCORES FOR THE SPEECH- . RECEPTION TEST.

Mean Scores Right Ear Left Ear Perfect Imperfect Perfect Imperfect Multiple-tone pulse-type test 18.73 2 4 .2 1 18.73 23.52 #1 Multiple-tone 1 8 . 4 0 2 2.91 18.38 22.43 pulse-type test #2

A further analysis was made in which scores for the speech-reception test were entered in columns according to three categories of scores for the better ear for the multiple-tone pulse-type test. The three categories of the multiple-tone pulse-type test were designated according to scores as 5> 4> and combined scores of 3, 2, 1, 0. This latter grouping was made into a single category because of 57 the small number of scores in the categories. The number of scores for the three categories was 69, 21, and 9 respective ly. Results of the analysis of variance are shown in Table XI. The F-ratio (unequal columns) was statistically highly significant at the one per cent level of confidence. Also shown in Table XI are results of t-tests for the differences among means of the three columns. Tests between the 5 and 4 categories, the 4 and 3-2-1-0 categories, and the 5 and 3-2-1-0 categories reveal significant differences at the one per cent level of confidence. The mean scores for the three categories of the multiple-tone pulse-type test are shown graphically in Figure 6. In summary, the hypothesis of no difference in means in the categories of the multiple-tone pulse-type test as measured by scores of the speech-reception test was rejected The F-ratios under the conditions in which the tests were analyzed were significant at the one per cent level of con­ fidence and the Bi-serial correlation between scores of the multiple-tone pulse-type test and retest for both ears and the speech-reception scores were significant at the one per cent level of confidence. TABLE XI SUMMARY OF AN ANALYSIS OF VARIANCE: MEASURES OF LISTEN­ ERS SCORES OF THE MULTIPLE-TONE PULSE-TYPE TEST AND THE SPEECH-RECEPTION TEST.

Sources of Degrees of Sums of Variation Freedom Squares Variance F Levels of Scores 2 2,203.31 1,101.66 48.98** Within Columns 116 2,608.39 22.49 Total TTsT 4,811.70

** Significant (F) at the ifo level of confidence.

Comparisons of Pairs of Means of Columns Headed 5 , 4 , and 3-2-1-0 .

Columns 5 and 4 , t 2 .72 * Columns 4 and 3-2-l-0,t 5.46* Columns 5 and 3-2-l-0,t 9.72*

*Significant at the 1 fo level of confidence.

Hypothesis IV. The fourth hypothesis tested was, "on the basis of two classifications of scores, the original multiple-tone pulse-type test and the same test under laboratory conditions are unrelated." Scores of the two tests were originally arranged in six by six tables corresponding to the 5, 4, 3, 2, 1, and 0 categories of the multiple-tone pulse-type test. Due to the fact that there were no scores in some of the categories, the scores were then arranged into perfect and imperfect categories for both tests. The example below 59

|_fr[i pi:; H tt^lrTEarr'-: ‘j

11;;'.; ‘ i:; : I'.'.iri:»: , h .;' j ” , . I ‘: % ri I v; ; vu<. ; , yi ; :, ’:; i . ■; i ; ’ p i

:*c. T-ziiti

a 60 illustrates the arrangement of the scores.

Multiple-tone pulse-type test (laboratory conditions)

Perfect Imperfect Perfect 2 4 11 Multiple-tone 35 pulse-type test (21.47 (13.53 (original

Imperfect 49 35 84 (51.53 (32.47) 73 46 119 119

(24-21.47) (11-13.53) (49-51.23) (3.5-32. ^ 7 .) - 1 < 0 92 2 1 . 4 7 13.53 51.53 32.47

The Chi-square test of independence was used to determine the relationship of the two tests for both ears. Results of the analyses are shown in Table XII. There was signifi­ cant relationship between the two tests at the 10 - 20 per cent level of confidence for the left ears, and at the one per cent level of confidence for the right ears. Reasons for this discrepancy are unknown. A further analysis of the data for these two tests was made using the Tetrachoric correlation. The tetrachoric correlation was used to test the degree of linear correla­ tion between the original multiple-tone pulse-type test and the same test under laboratory conditions. Scores were again arranged in perfect and imperfect categories as for TABLE XII CONTINGENCY TABLES EOR THE CHI-SQUARE TEST OE INDEPENDENCE OF THE MOL TUPLE-TONE PULSE-TYPE TEST UNDER TWO CONDITIONS.

Left Ear Right Ear Multiple tone test (controlled) Multiple tone test (controlled) Perfect Imperfect Perfect Imperfect Perfect Perfect 11 30 Multiple 24 35 Multiple 5 35 tone-test (21.47) (13.53) tone-test (23.53) (11.47) (Original) (Original)

Imperfect 49 35 84 50 34 84 (51.53) (32.47) (56.47) (27.53) 73 46 119 80 39 119

X2 = 1.092x ■ X2 = 7.690xz

Multiple tone test (controlled) ■ Multiple tone test (controlled) Perfect Imperfect Perfect Imperfect Perfect Perfect 64 0 Multiple 56 2 Multiple 58 64 tone-test (36.0?) tone-test (43.03) (20.97) (controlled) (2-93) (controlled) 18 16 Imperfect 43 61 Imperfect 39 55 (37.93) (23.07) (36.97) (18.03) 74 45 119 80 39 119 xx XX X = 58.813 3T = 67.47? XX, 'Significant (s2) at Vfo level of 33 Significant (X2) at tiie 1# level confidence. of confidence. ^Significant (X2) between the 10# and 20# level of confidence. 62 tiie Chi-square analyses. An example of the arrangement of scores is shown below. Multiple-tone pulse-type test (laboratory conditions)

Imperfect Perfect Perfect 11 24 a = .39 Multiple-tone pulse-type test (.092) b = .71 (original) c = .29 Imperfect 35 49 84 (.294) (.41) (.71) ^Ltet = .10 46 (.39) 119

In computing the Tetrachoric correlation, the Thurstone 's Diagrams for Computing Tetrachoric Correlation were used. Results of the analyses for both ears of the tests are shown in Table XIII. Assuming that the values for the Tetrachoric correlation are the same as the values for the Product-Moment correlation, a correlation of .47 for the right ears is significant as the one per cent level of con­ fidence. The .10 correlation for the left ears is not significant. Possibly a reason for the discrepancies between the two tests is the large number of zero scores in the original test. Since this score indicates that nothing was heard, these scores were not duplicated in the test under labora­ tory conditions. It is assumed that factors other than a hearing loss were responsible for many of the zero scores on the original test, for example, fatigue, noisy testing TABLE XIII CONTINGENCY TABLES FOR THE COMPUTATION OF TETRACHORIC CORRELATION OF THE MULTIPLE-TONE PULSE-TIPE. TEST UNDER TWO CONDITIONS.

Left Ear Right Ear

Multiple-tone test (controlled) Multiple-tone test (controlled)

Imperfect Perfect Imperfect Perfect Perfect Perfect 11 24 Multiple- Multiple- 5 30 tone test (.092) tone test (.04) (original) (original) 84 34 50 84 Imperfect Imperfect (.29) (.•Mu) (.It?) (.71) (.42) (.71) 46 39 (.39) (.33) a = .39 b = .71 o= .29 -tet = .10 a - .33 b = ,71 c = .29 —tet - .47

Multiple-tone test (controlled) Multiple-tone test (controlled) Imperfect Perfect Imperfect Perfect Perfect 2 56 Perfect 0 64 Multiple- Multiple- tone test (.02) tone test (controlled) (controlled) (retest) 43 18 (retest) 39 16 6l 55 Imperfect (.36) (.15) (.51) Imperfect (.33) (.13) (.46)

45 39 (.33) (.33) = .51 c = .36 ^tet = .91 a = .33 b = . 46 c = .33 ^tet = .95 Os Vj O 64 the Chi-square analyses. .An example of the arrangement of scores is shown below. Multiple-tone pulse-type test (laboratory conditions) Imperfect Perfect 11 Perfect 2 4 a = .39 Multiple-tone (.0 9 2 ) 35 pulse-type test b .- .71 (original) 35 49 84 c = .29 Imperfect (.294) (.41) (.71) 4 6 £-tet ~ .1C (.39) 119

In computing the Tetrachoric correlation, the Thurstone’s Diagrams for Computing Tetrachoric Correlation were used. Results of the analyses for both ears of the tests are shown in Table XIII. Assuming that the values for the Tetrachoric correlation are the same as the values for the Froduct- Moment correlation, a correlation of .47 for the right ears is significant at the one per cent level of confidence. The .10 correlation for the left ears is not significant. Possibly a reason for the discrepancies between the two tests is the large number of zero scores in the original test. Since this score indicates that nothing was heard, these scores were not duplicated in the test under labora­ tory conditions. It is assumed that factors other than a hearing loss were responsible for many of the zero scores on the original test, for example, fatigue, noisy testing conditions, or other factors. With this in mind, a further 65 analysis was made by omitting the zero scores in the original test. The test scores were arranged in perfect and imperfect categories as for the previous analyses and the Chi-square test of independence was used to test the relationship of the two tests. The results are shown in Table XTV. With the zero scores removed from the original test, results of the Chi-square analyses were 9*77 for the left ear and 2 0 . ^ 0 for the right ear, both significant at the one per cent level of confidence. In summary, the tests of independence to show rela­ tionship of the two tests revealed poor relationship for scores for the left ears of the two tests and significant relationship at the one per cent level of confidence for the right ears. Reasons for this apparent lack of consis­ tency are not known. With the large category of zero scores removed from the original test, there was significant rela­ tionship at the one per cent level of confidence for tests of both ears. Factors other than a hearing loss were responsible for the large number of zero scores on the original test since these scores were not duplicated on the test under controlled conditions.

Hypothesis V The fifth hypothesis under test was, “scores of the multiple-tone pulse-type test and retest categorized on the basis of perfect and imperfect scores are unrelated.“ Both TABLE XIV

CONTINGENCY TABLES FOR THE CHI-SQUARE TEST OF INDEPENDENCE OF THE MULTIPLE-TONE PULSE-TYPE TEST UNDER CONTROLLED CONDITIONS AND* THE ORIGINAL MULTIPLE-TONE TYPE TEST WITH ZERO SCORES REMOVED.

Left Ear Right Ear

Multiple-tone test (controlled) Multiple-tone test (controlled)

Perfect Imperfect

Perfect Perfect 30 5 Original 24 11 Original \ 35 multiple- 55 multiple- (20.30) (14.70) tone test (16.80) (18,20) tone test

19 35 24 34 Imperfect 54 Imperfect 58 (26.20) (27.80) (33.70 (14.30) 43 46 89 54 39 93

s2 = 9.77XT I 2 = 20.4032

xx Significant at the 1% level of confidence,

on ON 67 tests were administered under laboratory conditions. The retest was administered in the same manner as the first multiple-tone pulse-type test in these conditions with the exception that the retest was administered at a level 10 db lower than the first test. Scores of the tests were cate­ gorized in the same manner as in the test of the fourth hypothesis, that is, into perfect and imperfect categories. All 5 scores were designated as perfect scores and all scores other than 5 as imperfect scores. The Chi-square test of independence was used to test the relationship of the two tests. The results are shown in Table XII. The Chi-square analysis were statistically highly significant at the one per cent level of confidence. The Tetrachoric correlation was used to test the linear correlation of the two tests. Results are shown in Table XIII. There was a .91 and .95 correlation respectively for the left and right ears on the

two tests.

Hypothesis VI

The sixth hypothesis under test was, "on the basis of scores for the pure-tone test for subjects grouped accord­ ing to scores made on the single-tone pulse-type and white- noise pulse-type tests, there is no difference in the means of the groups. Scores of the single-tone pulse-type and the white-noise pulse-type tests were analyzed as independent tests. The single-tone category of the pulse-type test for 68 each ear was designated by scores in the following manner: (10 ) (9 ) (8 ) (7 ) (6-5 ) (4-3 ) (2-1-0 ) These groupings served as headings for six columns in which were entered scores of the pure-tone tests as criterion measures. It will be noted above that three of the categor­ ies of scores designating the single-tone test were combined. This was necessary for two reasons: (l) because of the small number of scores in the categories below seven; and (2) by observation, the critical point of the test according to mean scores seemed to be near seven. The example below illustrates the manner in which the tests were categorized. Scores of Single-Tone Test

(10) (9) (8) (7) (6-5) (4-3) (2-1-0)

20 (Subjects scores on each frequency for each ear were entered in the columns as basic measures.) The number of scores for each of the categories of the single-tone test as categorized for the analyses were

20, 28, 18, 10, 2 3 , 7, and 13. Results of eight analyses of variance are shown in Table XV. The F-ratios for each of the four frequencies for each ear of the pure-tone test were statistically highly significant at the one per cent level of confidence. The greater variance ratio is between the single-tone test and

the 500 c.p.s. frequency of the pure-tone test. 69

Scores of tiie pure-tone test were entered in columns for the white-noise category of the pulse-type test in the same manner as for the single-tone test. Scores of the white-noise category of the pulse-type test were grouped in the same manner as for the single-tone test. Summaries of analyses of variance for these tests are shown in Table XVI. The F-ratios for each of the four frequencies for each ear of the pure-tone tests were statistically highly significant at the one per cent level of confidence. It is noted that for this test the greater variance ratios are for the fre­ quencies above the 500 c.p.s. frequency of the pure-tone test. It would appear from these analyses that the combined tests of the single-tone pulse-type and the white-noise pulse-type tests are statistically more reliable than if either was used as a separate test. Table XVII shows the mean scores for each of the fre­ quencies of the pure-tone test for the single-tone and white- noise categories of the pulse-type tests. These same scores are portrayed graphically in Figures 7, 8, 9 and 10. Although the graphs show poorer scores generally on the single-tone and white-noise pulse-type tests for low-threshold scores by the pure-tone tests, the greater difference is between the general patterns of the single-tone and white-noise pulse- type tests. ALthough there is a gradual decrease in scores on the single-tone test as the pure-tone scores increase, TABLE XV SUMMARY OF EIGHT ANALYSES OF VARIANCE: MEASURES OE LISTENERS SCORES FOR THE SINGLE-TONE PULSE-TYPE TEST AND THE PURE-TONE TEST Sources of Degrees of Sums of Ear Frequency Variation Freedom Squares Variance F Left 500 c

**Significant (E) at the 1% level of confidence. TABLE XVI SUI/SMARY OF EIGHT ANALYSES OF VARIANCE: MEASURES OF LISTENERS SCORES OF THE WHITE-NOISE PULSE-TYPE TEST AND THE PURE-TONE TEST Sources of Degrees of Sums of Ear Frequency Variation Freedom Squares Variance F Left 500 c.p.s. Levels of Scores 6 2,946^66 491.11 7.03** Within Columns 112 7.812.63 69.76 Total m 10,759.29 1,000 c.p.s. Levels of Scores 6 7,875.16 1,312.53 8.93** Within Columns 112 16,454.77 146.92 Total m 24,329.93 2,000 c.p.s. Levels of Scores 6 22,164.10 3,694.02 16.45** Within Columns 112 25,145.40 224.51 Total m 47,309.50 4,000 c.p.s. Levels of Scores 6 20,807.93 3,467.99 11.63** Within Columns 112 33.394,36 298.16 Total 118 64,202.29

Right 500 c.p.s. Levels of Scores 6 4,812.41 802.07 7.30** Within Columns 112 12.305.56 109.87 Total n § 17,117.97 1,000 c.p.s. Levels of Scores 6 12,901.86 2,150.31 14.62** Within Columns 112 16,475.89 147.11 Total m 29,377.75 2,000 c.p.s. Levels of Scores 6 20,624.10 3,437.35 12.69** Within Columns 112 20,347.77 270.96 Total 118 50,971.87 4,000 c. p. s. Levels of Scores 6 26,943.37 4,490.56 10.02** Within Columns 112 50,177.18 448.01 Total 118 77,120.55

**Significant at the 1% level of confidence. TABLE XVTI

M E M SCORE YALXJES FOR THE PURE-TONE TEST IN SEVEN LEVELS OF SCORES FOR THE SINGLE-TONE PULSE-TYPE AND THE WHITE-NOISE PULSE-TYPE TEST (MONAURAL)

Seores-single tone pulse-t.ype test - left ear. Ear Frequency 10 9 8 7 6-5 If-3 2-1-0

Left 500 c.p.s. 1.55 3.07 2.06 4.20 11.39 15.14 19.08 1,000 c.p.s. 17.45 20.07 21.44 27.10 31.43 42.00 36.92 2,000 c.p.s. 6.35 9.68 13.94 16.30 24.52 40.57 24.77 4,000 c.p.s. 23,75 34-25 29.00 38.80 44.30 51.29 49.77 Scores-white noise pulse*-type test-left ear Left 500 c.p.s. 4-57 4* 14 3.61 3.53 9.35 12.22 19.91 1,000 c.p.s. 21.48 23.14 21.25 21.12 27.88 30.67 49.36 2,000 c.p.s. 6.61 11.00 8.79 10.47 26.71 23.89 53.36 4,000 c.p.s. 30.48 33.21 30.79 23.94 43.65 42.67 73.45 Scores-single tone pulse--type test - right ear Right 500 c.p.s. 1.41 2.06 3.29 6.38 IO.54 9.78 26.07 1,000 c.p.s. 19.54 22.81 21.24 23.88 29.96 30.78 51.47 2,000 c.p.s. 6.82 12.38 11.53 16.50 19.63 21.56 39.20 4,000 c.p.s. 25.95 27.19 29.47 27.19 36.46 47.78 63.93 Scores-white noise pulse--type test - right ear Right 500 c.p.s. 1.31 3.95 4.47 5.06 12.22 7.42 21.59 1,000 c.p.s. 17.77 22.42 22.63 24.44 28.06 26.92 52.29 2,000 c.p.s. 6.76 7.83 10.11 12.56 15.28 27.33 46.41 4,000 c.p.s. 24.54 22.04 26.84 30.44 38.39 42.00 68.53 73 &V. ■ '# , -Ijjj -forj c » p . 3 * - .toiie:. t p . ■ i o :; .;;: i .[type jteSjfi ••; ’);. .. • ; : . ; •. .,; ; : j r-| v: i :j :,, >£>vj-( Bobre "i: T ; ^ * l-fffflif Kxr^ '!': I j.! | r | ; O ,, is-1-- p ; 2d: .-p..■ ;i;p

;0 VTT-'1-' MM J- r • : > i ■ ; : •■ - • I; •' I] •’-i:.; if;.! iljJTiilH-Pir!.' r::’:!. ' ■! < r! V;7r fi r ■ ' ITHVrtf 'A'-A ;■ fp'.i.: :. . . . • , - i ; t r■A *h. ' ?■ * .. ( ; -jy-. ■■' r-^Jf t v! 1 \ \: ■; i:;:: i '! -j , [I'm” '1 : ‘ i . ; ; ’ . • i • - -. r‘ | vl j- t{ -■ ■fin jT' {■', ■itf-' yi'p-'f •jrtt'Trt■■ u rpT:;TijT n :l ^ 0) ,'* . 1;.^! Q> * ■! •. »- I Jf\ \ t r - yr,j> 1 » , - • ' » ‘ • , y ,lx- ' ■ i / V; : ' ; ■/■!•..: : ' ■ I • : , I ! ;-o - . [rcJ-;.■-. ,niriin • ' ^1-7;; m I'g-i £ s 7vi|i I : !>>•• ; ■ i ‘cj •; J. t! ■M r. .•:■:! j rr.i ■] i■ I a> ■ i -CfiT'l i!*rj : . i Ti :P--•-H.rt.s. l:i!,;

■ •I ! ;1 . ■ .! i ii i ' ; : I :] 4I; ! i1 i‘ ! 1 ' r‘ • . .> : I 'sa ■ fci1 i *' '

3 1 1 .. ; i^PUflTUWR^TIinWTrn f . .. j - J .... - :-;- 1 j- . ,-i ■t-f-*; y~i ^ . ,T i i!' *-,-f ’I i ^ M f e j-j y. i i'r!!Vi;t;i *...j ^ ;i: : , , .j-,.’** i::■;:; ; • -r-r i ■! i . P» ; p • | -m * 7 - I f \ i ' i ' ' ' : i ('■ : ; | 1 } ; i • !' . ; i ] : • -1’ T;"*4! I ' ii 1 : !" i ' ; - ! ‘l + ^‘f ■ f] i ■ ■ 5 • ! '; I i : 1 I ' JT'’l f IJ, ’ ' I 1 : I } f • ‘ ' ♦ • ! 1 U • * "U •; :J. i -ii • i i i . t ^ ± v - i j j.i.1 >Jt vLH,:_d ■ i • U ^ :h:!;i:”'ii[i;ipl!ril! Pt.; i • :v: J n j.i | ■ ■ j ■ .jtj=; H i;! I:! "n i; i

::: .-J":!■???=R]--111PVt*■ 11;i!^1 ts-;;;RtSl=Jf.Jljf!^iTi li.iltai :Vsiv v:■ ■:'vL'::■!:vt i ; b y H i J f , t L f * ! • ! i 1 -i •* . ! "f : ' ' * ' ^' - ‘ ' T‘i 1 ' l'T: • i ‘' f ‘ 'j " *'! J • 1 "■ >'d : r s ' 3 ' f''' ’j4j *' - 11 1 :— • r i * M V i L xdiViliaiUiiLiii;iri:-!i! t No. T JiUO C. T U B K. COJoi: GU., ''CU.CMnUS. 74

jq !' . for ea'Oh. category ' ...-, . 5 . 0 0 c.p/a, tone -— ! - — . i &; :’■!:. single-toae pulsa-. . j.> 3 t ,0 t o n , ■!’ i ■ ' ■ -'It: ■ ii ! t • : i : : ' ‘ i ; !'■ !'■ : : i' 2 o :;| |v::-':Sc< 5 re;:f;jHp'‘p ft!]‘jitpp!: •

. . ; . Z Z ■■,. .4 »id!fc.0r^C . fci.'si..! :t d i i e . l .L w . v I ..J :j

O ' . " ; 8 :■ ■ i •; * - .'j{' i -:-i-fVH i ...... ;- T'TpT:^ r ;. r ■ ■■r • “}• ! " 1 o -{,-; r' :.»5r--fj-; 1 : : : v - i u S l } ''■ •!! T. i , i' I r ' ^ ...... -.. r. !. ' : ; ; i o " ;v ; 4 - 3 : ; P 1 : P - l ; h 9 ' p H ;n:;v p ■ .y .::! ’! 'H 'T f: t : ; I.;:-; jr.:; • •; ! o |§ * 8 t y **¥&?- ^:::::■ -i- j ■ j j ■ ;.p .H • •' ;-i f- l'4il H i P j ! H H p U p : T otal; p; :: ;; X l9 •: ! ' l O 1 o ■ ■ i

!&■ 6 0 *1" i ~ V .... ~ r-'-'-r • I ■ • . - 4 . P;PPP'P: Pi -P ; Y p H t Y p - , • r ! • ' i. p :^ ■ tK-! i pHlli-pP.rl.H p P p p p .;- Ypi, .■ L ■ rJ : I f .' H _i : ;l j ^ j j ' :h-i| t ! 1 ^ i ' t r M - :.prYI.'' 7 ••« Y .Y t • :.- Y-M- - •' ■ • ; " ' - • ■ ’ ■ r -I; : . I i I - ! • . | ‘r ' • - i f - ! r ■> i+> . i : - i. HS lv*i wtm^•i m L - i i ! ’•' im1 '■ ■: m nf:I:III;y m | T ; m V L | “ip Km :K!'r: i 1 : m I / ! : ' : :: l-j : :i}i4 aj ; ;’:i (' ■. ■' .vrt ; 111;;! ‘ i >': ,.: :':T' H .TT.D- i: 1 H i! : ,' i 4J-11 -:i:! :i1 ’:!}: >J: .!-; jr.:^, i ‘ t i | i :.>f; ■•:!.: i :- ' i • IV ! V v M \ \ ^ i I! :l*-! i - :! ’rsltH .Y : : r -rr 8 ^ p ;H UjjJ;iijj;k :; '1 h > -36 i: • ? ! j M i . - , p l: - -\ j-i:: i i • 1-i'iI;v^ : ;n m I - ’ ;-iJ

I

W : ; I,';' Lti> ■' j1. ; ® } n -.1 I • ’ ■ • - P i ! ; ; ; S i;.;:!, ; r ' : -

i i ! ; S p : ! : : * « i ; p ^ HTrl r } p ^ !

v r>;: 1!: 1 Hi i>:7f V ^ \ ' T < i; i ijt! ’ H i : I ^ ;!-!! - b !;: 7 H • n: f : T:;: :1 - \ : Yvi' ’Ti ", ■ 7 ' • T: •: .7 JI r:".r H• ■••! ’. SiHnRle-Tone}.-.'F.ui.se- 5 * y p e . T fe 91 I;:::;;. .Hlghtj' 3 r . t • ; 1- • ■ I ' ' ; 1 , [ ;.■ I Li i.: .•':: ; • . i • i Hp!rouiREi..P^:l . |

... T.„. .. .. a m RisiiAirii:oNSEip:: ,|\.;.::

;:, • ;-U j j m p w p m : TtUS :MELtmi SCO RES . DR. iTtljE R U RE-TO NR iO'ES'P : 1, ; ; ! ' H|-; HJ j .x :.'.. i: ' . J ri.l lI.IPI':

V ' ' ' ' - P:7;;77mj< r;V';P

N o . T - 3 M O. TJfE ML U O L K CO.. r.'KLU.M ill K. CHtO. 75 p ’ TTrr—rrrrrrrrTfTtlTi‘;TT ‘ ; ' v . ':: i' ir: ; <.'

: „ X ■ ...E'-tot ■: jaaft^:^jajbQ^6Ehr;:'': , 000.:; P * PVS«_. :;L!_ 14-A Li'-'■

i . « r. , -i.: - ; . j- !■ typ^iliies^! Pjju:;T.Vrl0!-P f * - f f c ■; | f R - & 3 |TJ 1 P f P 1 f &

! o' : S' h L 3 ;...... *^V j -* • •* • !-■:' r =■:«;:- j--; - ^ 1 h ^T'* - • “ f - V l .i.. i l». ; - - *».... ,-'•/* »-!! 4 - * •V-'-r- frPU;:.i .. «.{ 1 -j: - -J- : : ^ ; - -J-.— ]h-i-i .)- ■ '!- ',:;'I I K : :' i-' :M".p v ; ■1 <1; : : : L v r- > r: - i M ! ,: : ; ' : • ' 3 T.-f -i. ■ 1 :' M M r

' o " ' ' * f—t ■. .j • .■MuLi.M. / il7 !j M:i :''«L ; ! § ^ , ‘Aiij-I . .4 ; : r HH'iiMthLiMlLM:i:;ir:■■ :-f;- ::L -ii-i,:-f;4h|-;-p|-|i. 'H 1 : j-t;i I 'iili* , h ;ih j'rl '-jiJ ; : l:;,'»-::i"1-. : M M !' LI - -! ■ i •: H i1'! ■ ■ ’ I-1M - ‘/f ' i - f ;'I

i - + z : ' - 'S'l . vfLr I il-l-ri.’;' jMi;:; jivf l.i Lr: i.L -ii ;: | u ;J / Sjl44 H i > 36 ■; I , j j 1 1 ' }•; : ; u ! ; MM iil.ij-j i M j.i p - ■!' : ; i t ■ j M i '. ;: *' *i I ■ i-|'j i :^ J '' •

:]_

• ■ H j i i ‘r,■ M.IV!:M: |'-,;'!-i.:iiJi:';:.':;'1''l.£ i i;1 i i ':1.: ji;;' .••; ;ii;if: ; ium [!iti:;-^11[Iir:L ir.rj -iPlr'^ij|^r':■ ■ r. i i

[ * ; ! il-ii l-j!; j ! ■: ; !i J : I '"’-i r I: ■! ‘; :£:.:: > > ^ 1 M ji: M M :L! ’ i-:: i X X* p r !! .4 f : ■!: - - Ly'-* j ^ ^ I ; j . ! p !'_[ I- I J v l p i M §\_-ir -'m }‘4-[-i'v!S( ; I L.|

;i n! '-:i ,M; ■1!!M!:-j-j-t;;! M;i ' Li; 7: i - r : j tvfL !-rf;!P p-'I4r i K4-Ui-'-=-I-t^ : j- .1; -i-i I: IM--* ■; ■ i , L,-r jr : - L :-M: ] . ; ij Hi1''■;;. i -:-4 ; 4-{-: • -id., + n j-■ j w1'! r1 ir ,3-i ‘-l m"i-' •j j"H , •1 * ; • . i" ■ • . - t '-in ' , j ■ '• t ; 1 j * i'-1 ■’ ■ ;j M I- ;;rrjTi,1 ]r; r T i.m ;:; >i i ;.h;*•■•■ ri ■ i ■ i>:»■-■ ;;?• . . i . ^ u n -7 1 v mm J H i t-r-rrK -; -1 '•• ’i'L* H i ! '-r±J • ••• >-•-! • ; ' > '••Lj r i • ! : . H 1 :■>■•! !i-t f I'i 11 t'- i i p l p p :$i g jfti i fe s ! MlM'i HI'. ^•3 iiM i' ^itrrrr.jvip-rtriip I rr'i r:’ r.‘:h rr:11 ;T.T;.tE{-jTrr?.rl"TT ; !•• h.tp I ;ji ,,!-! •: 1 i- • 1 • . : . ( l ’ ' i \ a:S:t;Jl . : ’' M ! "ire; ' Ml -. '*7'i

;:'..i ■': 4!: ^ • .;€j^AEHX<3Lflft■- REPfipESENTATIOH Ofr I THE i ESLATIOHSHIB m m

ipM I M WM iMTli LfiTf M t e p p M! --TM'Ml i"i'""■ M;; irj:Lri 0 L illM I ifn'm

.•Jo. T-zvo o. n o : h . toue coi.yv:-»i^. omo. u. M. u .a.. ■* »-i ri • ; * ' £' * ' ‘ * 1 *" ‘‘ " * '■ ~ * ' \ '< ‘ •' • ’ '■ ; * : M i < P ’ i 1rtnr s *;ji.q.ji 6 : x | ::: - '■•-■i

■ x / r P - ! ; i p , p -1 :ii: ..• ( ;|.:.ii'; > b 5 c * ^ ; ■ Hi-; ‘ f v : if f ! i . | T - h y l ■' I h r t H W" - k “ '..... ^ S ’^...... - k ( 4.. U...... U : " •l' ■' v ' . : '• I [' : :1 u p r j l i

. jfpgi : x : x ' 7 ■ '} j i-j 1x ‘ i X ? : !' : 1 • ' -i-,'! ’ * j |; i I f '*■',• i - ";y; j );' j-‘ t x T p '■ 1-f- j ^ - J : x| ; xv;; 6-5.^ pii!?' rr> -p -";« :: frl rfjH \ l;jp#

! Tcrtai r‘ '■ j RriStife'^-:-!■;■: X:VL - :ii::,: ] \ :; px pxfi f ;; ix •;:i; ■]it! j ill ipiIp S ; ip p t x P ‘Pi p jriirHiTff/D :T .:m Ip 7;' ';T;:’ p :'yr!y; paptj< : • 1 Hi ' i-i y :'t ' -iip p k xvP ii‘: y H x P ; ■p I p iy l;4i! p i ?NI'NPj I x P ! i i ! Jirl-J:] y H'11: i~; ::fL ; Pii-iNi x.Li.G.!1 !*i tri'+tix' i ;1 •.••pi 1 ' ! r : .-ij t - y , -f i - i ! I'T P‘! k; ; 'i '1 4 * f ''^ ! Ff"T": i * * ' : ' > ■ "'■ ' I 1 "* * H yliJTHj' ;•;,■;■!; iW i" -!IN '■’!P l P y l : p N t p ; ; , ; P p ; i f r : ;>•:: 1 1:-: r-i-::i.:, p / p p p p p p f e * r ,: n i t - , ,..., f j i - Ikf;!! I Ii I ;N: Hi: INI i|lNvn^piykl||] iy : yrmjp^ ;NTiNi ^:p^i Ht1 -1 1 ’;: § H j: i •:; nT;N:Wy:r-;4rni:r;]iyni )\h‘yn0\t\(\ N ':rarn" -| ‘-7r^:rN-■ ln>kTrr; .y i:! ynLNzini' h i l y ii'lkblH ii j-v.; !J ; : i l \\w$ : ; ■ i" I b l-iyl h : i-i ■'■: i-■! m ; [H i ; f- N 1 1 , ■ :iT i l ! 51

j !Tl S p ^ ^ ^ 3 i!Spij^^ ^ 1 : ^ 3 • i •; :■: ■: ;■•• ;: i ' i-;-‘:T-l > W : i / : : U I ;. ^ , ;: i : ■: ■!1:!: - h - n ir: v-:

TiJ;yriT^w^ ' ryi •? fj •:' ■ -fgltrn-Tt^ imFr~ypJ''-rT: iiU4iilJ4ililiJ:LUjLHk^ !.t ■ i . i . ! j: |: n ;T[ 'i ‘'I 11 v -H i J Iddr; - jj^Hrrrnrnp^^^ i-I r j m ‘;; IS iSlf f;i: f'*' H: r:'! ityl vl ■ ... I'ixr'-rh- Y f j HIT5 HMrtin'-iit-V '-!1 pxbij- i N • ■ .?•;•■ : :;T '! i ; : :1 fjr: [ 1: : l! iJijj jf|jg i||]^ ;-. ■■; i ■ i,;-; j h hb i rrrfrftfn-b •p->H ;j; !.u ; v r!:[ jJ I;: - x ! tgjr y i x |-Tt-fpn ;:!ti :!vTMiitr:Hvlillllli-H:! - I ' t q SvJ-UHi 1 ! j ii J i i j i v Jiilv j.tiil ■* S.*. Oe^^d|iL|p..!y i,. jk-- L vii^.— -l-T-'-t--; N ;.r ij:;y n vl i 1 1 ; : . j '• V r i - iiflV'i'i 'TJ;Til'’’* rPTfi1: ;'■ ■ ;Ti ■ ’ 1 ‘- Ti::n r\ Lj‘:/P:t:i~;'; '-ix'’ ;-Pj 7; i n riTl’!i: vi^-lT! T'f1"; •' • • 1f ] -v'' '-S^ / r ;:7t i ; •;. i . vm _4L;.i:.:i !4 ^ ..4i::. ; x : iF .tG U R l! ;iOL.; J.j. . :! J.' 1' v! ^ ..i V.xL . I L - j tr: ^ r.; i ! t rTxHi.r:" t : : ; x ■;■■ = ! v ' ■ Ll'. ’ .' i i ; 1 ..i i x • ii; ■ H x .- ; > • :. i • •KEEKiE'SlSK'JAffXQN-: .0 $ Tllia l -J ^ A fe € iK S ir ii^ : • -. I ,;|- '.-N P; ;i ]j-i 1 'V i-l - Pi 1 ' •’ ; ’ i r ‘iii :MfeAN: 'iaq QltESg3|ii .'M}.: j l B t R § I k ® W I 1 ^ -■: i H Ilf! >! P i t b V vj

1 ij:{H :: i;.; M i ;■!! 11 - p !v !-ii !! I-i :,; , v : ':: • r: t- ;: 'l h - - : , 'i i i l ,"'■ !■ H pH'f -it■ :|-!!.i x Pvv r!,i 'h; p T ^ :I i l T " : ! : : : 'ry y yI T t : .; y T t l i d'NTTfpN: 'N ■ n®: T n i ^ r ^ * i y'1 ipvjirxPr'Nixt.Px. trt-vp1;- ’ • lfpplvv. ;ll :-p .viv y p !:-: i; • L.!: x -vj::, {I :f;. Up I Ip i.M

I’tr. T*2UD G. TliK XI. COLE CO.. COLUA? VUF. O l T I O 77 mean scores for the white-noise test do not change according­ ly for the seven through ten scores of this test. This would seem to indicate that the single-tone test scores of seven, eight, nine, and ten are more predictive of pure-tone test scores than are the same scores for the white-noise pulse- type test. In summary, the hypothesis of no difference in the means of the categories of the single-tone and white-noise pulse-type tests when scores of the pure-tone test were used as basic measures was rejected. Results of the analyses of variance show the tests to be highly significant statisti­ cally at the one per cent level of confidence. From examina­ tion of the data, it appears that the combination of the single-tone and white-noise pulse-type tests are more reli­ able for tests of the frequencies 5 00> 1,000, 2,000 and 4,000 c.p.s. of the pure-tone test than is either of the pulse-type tests alone. While the variance ratios for the seven-through-ten scores of the pulse-type tests are not as great as for the lower categories, it will be recalled that in the original calibration of the level for the tests, the levels of the pulse-type tests were set so that the last two levels {columns 9 and 10) of the tests would not be heard. 78 Hypothesis VII The seventh hypothesis under test was, "on the basis of scores for the pure-tone test for the better ear there is no difference in the means of the scores of the single-tone pulse-type and white-noise pulse-type tests administered binaurally. Eighty-five of the 119 subjects were used for 3 these analyses. Scores of the single-tone pulse-type test 3 This was necessary since it was discovered that the level o f .playback of the pulse-type test for the first 24 subjects was higher than for the same test administered monaurally. were again grouped as follows: (10) (9) (8) (7) (6-5) (4-3) (2-1-0)

(Subjects’ scores on each of the frequencies of the pure- tone test for the better ear were entered as basic measures.) The number of scores for each of the categories above were

4 0 , 11, 1 6 , 14, 17* 12, and 9 respectively.

Summaries of four analyses of variance are shown in Table XVIII. The single-tone pulse-type test and the 500 c.p.s. frequency of the pure-tone test were statistically significantly different at the one per cent level of confi­ dence. There was no significant difference for the other three frequencies of the pure-tone test. There Is a possible explanation for the discrepancy between the single-tone pulse TABLE XVIII

SUMMARY OF FOUR ANALYSES OF VARIANCE: MEASURES OF LISTENERS1 SCORES OF THE SINGLE-TONE PULSE-TYPE TEST (BINAURAL) AND THE PURE-TONE TEST SCORES FOR THE BETTER EAR. .

Frequency Sources of Degrees of Sums of Better Ear Variation Freedom Squares Variance F

500 c.p.s* Levels of Scores 6 1,805.97 300.10 7.60** Within Columns 88 1x473^4 39.47 Total 94 5,279.31

1,000 c.p.s. Levels of Scores 6 1,433.54 238.92 1.52 Within Columns 88 13,805,77 156.88 Total 94 15,239.31

2,000 c.p.s. Levels of Scores 6 2,025.94 337.66 .98 Within Columns 88 30,466.94 346.22 Total 94 32,466.94

4,000 c.p.s. Levels of Scores 6 5,243.38 873.98 1.80 Within Columns 88 42,753.21 485.83 Total 94 47,996.59

**Significant (F) at the 1% level of confidence. 80 type test administered binaurally and monaurally. It was found in the test of the sixth hypothesis that all four fre­ quencies of the pure-tone test scores and the single-tone test were statistically significant differences among the conditions at the one per cent level of confidence. It was learned that the pulse-type test used in another test situa­ tion showed considerable fluctuation in test scores on re­ peated tests, that is, there was a progressive increase in the number of correct responses through the repeated applica­ tions of the test. Figure 11 shows score values of correct responses on repeated applications of the test. There is considerable change in scores from the first through the third test. Since the binaural test was always given first in the series of this pulse-type test, possibly this is the reason for the discrepancy between it and the monaural test which was given third in the series. Scores for the white-noise category of the pulse-type test were categorized in the same manner as those of the single-tone pulse-type test. The number of scores for each of the categories was 37, 8, 21, 17, 20, 3, and 11. Table XIX shows the results of the analyses of variance for the white-noise pulse-type test and scores for the better ear for each of the frequencies of the pure-tone test. The F-ratios (unequal columns) for the four frequencies of the pure-tone test were statistically significant at the one per cent level of confidence. Table XX and Figures 12 and orno ••j/!MK»vn» ' oo jricu m jiu *d OSS-I,osi 'Ory

■;: i i;^!# r!' i;l; ■H: j'.' V.=1t ; ^ j;:^ tip I [■'■■•'■ rC ;,*}.-^ !:■ I ...V •: • ! ? : t ; ::• r ;. ; p i : :■. V. j.. •.:■ ! r ! j : iijr-iiift h-H■;• tlii}! j; ,:'.!: r!j ■J ; ■ ,\!.'.i;!v!•' 1'ivt! Ly j. 4 i P i 1 f t i p ft jiiljj;';ft jli fit

}.;: ft:'v : :■ i p iHtjxjji-as'iQ^ I ■ Wi-HfeiKis: $ m i s d : sa*sKfef.i 3- .m hp -ft-ft i f | - f t .;•••;

: •ii :i• fi -■ ; iifiii'ii!;. . i Kr^lr■iii-UlULl T]T+ ftftI ft ."ft ift ..aft-: i ft > -ftiiihft-i ib

L.. .4 h; J - ' i : 'lil:*■ J2=rr!TIj: 0» l y . :' 1 ' ' ' ■'!:.. ' j; : 1 i I i i ■■ i I ■• : v i i l,' ; ".[j-'i'1-' ■fhv‘ ■ t f 11i 1 •'»,CO rn; : ,- Oe+>'•. s . 1, 'i' 1 ■ !..o i j £ p L : J . j P d . :... t ip:.i.4.SiaM-1 L i p ] ^ . IS t : iSlSl / r. , i .. - v* • ■ . - ;,. j : n • p : : ■ i , , i :•:;;; ja! :o ■, , ; Il:''< ;. . \. ■;i' I - j..],.i..-i.iii:'j .. j...li:'j...... ! J : ;.. t..>:>i; ’j(j^ J-l • • Tfr/'ifur“jirp! ■. ■ t •: :':'r :•;:: ;:r ;:.T'v ^

; I' i1 r.i.: i I rr[t ;in i-riiTr'iJTt-; 1.: .• t-':r : iri v * ftr.\i ii;,: !f i i m i fi:’,, 1 r

’ :4 :; i t i !; i j . i- r U ’! r.i jCT .. "1 ;j: ■.:-4i;i T';:i!;:pbib!-:n'b10' " : - ' : - 1-1 ^ jiffy.. ,.p.j jffl...1 .: I ■ j .: . i;:.. .1 : .-i : i ! \ ’ ; l m 1 ■., I ." ■ 4 ■ j ■ ;-j . ; ; r.!-i • ; • , ' > j;f ■ , - ; i^* (. : i , ,-J i ! ! i ■' ' ;' i '' ' iij '■ '■ ’ j ' ’ ' j l ,‘j ' : ' ' ' l * ir ' ' ’ ;j ^ ;L: fi; ...... i-: i i- ji ^ piITi- ; -f;f;Ti;:[vi i j i " . .... ^ i [\;4 i : i ; T : p ^ ^ ;p ^ i|:“'; 7 j " ; T ; . ; r;i!T:T‘jT;:T:T[:ijir

!ri . ! I * ’ 18 1 *" • TABLE XXXI

SUMMARY OF FOUR ANALYSES OF VARIANCE: MEASURES OF LISTENERS» SCORES FOR THE WHITE-NOISE PULSE-TYPE TEST (BINAURAL) AND THE PURE-TONE TEST SCORES FOR THE BETTER EAR.

Frequency Sources of Degrees of Sums of Better Ear Variation Freedom Squares Variance F

500 c.p.s. Levels of Scores 6 1,532.64 225.44 5.62** Within Columns 88 4,001.35 45.47 Total 94 5,533.99

1,000 c.p.s. Levels of Scores 6 3,752.23 625.37 4.79** Within Columns BB 11,460.40 130.46 Total 94 15,232.63

2,000 c.p.s. Levels of Scores 6 6,261.61 1,376.94 5.03** Within Columns BB 24.075.27 273.58 Total 94 32,336.6$

4,000 c.p.s. Levels of Scores 6 15,166.82 2,531.47 6.79** Within Columns BB 32,807.77 372.82 Total 94 47,996.59

**Significant (F) at the Vfo level of confidence. ^ _ (______^... ^ _ r S3.

1:^?. ••••:•:-;•- -i-S : ^ 03? .fl£ 4 & it S .-itiQ ftb .i „ .’’ ; i.;.L,QQQUCUions . f i l j

I'OT.i"! ;H-^v:r ;j;r if-V ' “ i"..- 4 > 0 <^0 t 0 ^ . S , -'1tfne... L^r.-rt ;r

i ': ;|!i i l i i J t e l i S '■ !( i i l M !ii:lj!j!;' ':i i :ikit! ilL'i^;:LJ ;: :i''-jJ-: t.ip.L’ L; J ■ |Vj’’ i^;Ta'[ lu U^rTE^^ri ■ CS a ^ u : '!• ni.: ni: rr ■;: -: ;!

ir#=‘i * "i ' *X 1:i' i i *'* T'^ 1 ‘ ’iLL ' ‘ l'vr\h» 1 *J t[* ,m *"‘ -- fr-* ^i>-: ; 11 J_h" : "i *’ i • r . 'i. ■ 4:■-“i * . • t 1^FSi^iTiMgfTT^-ir^nT^i ; •■« ' • * 1 : ;• ; , >jt f r i f m • , i • t • < i »•. • .s: i^1' TTll^LRTrSfri:; ^il.;.;:x_fis.;.rl.ij-'.'jj^k; M r!>^ TTH [!?; ilgiTTTT;:~) I i: •';! I * .:: ■ ^ f •Hi: ;. r! Tf' r' ji~;Y:: j I;:.: i' r' -:i i: : ^ ^ r T ! :v::; ‘ L': i

t .w ?.:.: i- u.f|A:u:..U'ai.

'- , i-’ r i1 -; i - •* i r,'1'! • !!'!-! ‘J ■1 - *1-;T};; 11 ;••T^thTn’nTnrii^ntpl^vri-^■ i "•.Mri: ■■" irn'?. txy .:i!!:::fiilfff f i l l i . " i - T : l-i •ii:#$■ +u JTTTTtp^TlTFTi^^^ni^ T 0 ;• f • i ’-J-r : » j [ t ^ ( m rr * ! +j ! -rM-t \ ) itv}v j T'l^' - Li .■to.--.ip2-. ;'J.:^lj.:.Li,:!44a:L me-..VilliS**;

■ I ;

t;t; 33j '^'|l"i’■ •!•***•• , ■-]• I-v*'hitl'r!'l1 t'•T i 1 :"'l'i"''! • f f n - p l t r f " IF l-"1 -U U U i !-| i t r j 3 ■"]!■-!;.| 2-1+0'

Ijfiilt.'tjiTii1-! Hr! V’M .•!5f.•■';!ij-O ; !'j -'--j .1'!j ; i-j!| rl:41ciij'i j.|4J-.-J-••■.ijlirtj-!'i'll ilHiJtJI 1: n-i- rLpjiii-.-jliui*ii■,-:+■!. ;.Tr.: ;ixH^i_l|j^- lir'll!'| i' i *' , rii! |;i11 ‘ ji' |;. •, | I:; i!;;!■ :ii|if Mlii-: .': fi a r r ; a i ;®;vi iff il a ap t! Jfseftftft: ifj r;tj^ Til n ^ |1 ;■'! I j: ]:! r : ^ i J" i ;ali-Hi-r|-il- ait1 njaffr H I^PJjfe^TCTJn^Anw Off‘ ______., 'S,:;:'..: ! ,iiBKWTONiiTHEi. M E A H i ^ G d H E S • QJ’i-.yHE^ JP.tlRE-TO.KfS' T E S T ;.i .:"'‘ n - 0 }|:njp^gp :better ea|?:.^di scores,uts;yielded bv

.M.l : 1..; '.C '. {* f i i f e :f t * ;‘: U }: ,.j , j ; . ' ’ •! 1 • . i i • > -v - ■. I (*r(. 1 : T f'l .u.fI *T ,. ■ * i 1 —v 3 ■ i. ‘ j . ...; L L L .. ' ', rl .. i 1i r--j. i \ ’ .J.. . K i;i;U; J!. liiilAj-nsiLi:iiiii44m4:;i.;i:‘J ...:v[^i . iHt! ' 'J!li r i 1 . H '• • r* ' : : I : ; r.. t 'TH+rr vrj.a U.U: ' Ji 1 f ' »! • •‘ J ■. »■ ‘ ’, ' ;! ; i f ’ .. :■) -, • -t: : a j f . i . I1 ’ i!-: lv l .. ^ J \1 iiH-NM a ■ ■' . i -t L !r: ^ . 'rr - i n 'I* ..! ; ' ! '• i .U-i-'J .vy.uit>s, Oiii-.* 84 k £ . ': :.'s.•'.{•!H U i : r -1; --'Ii.;.: ; J. . ’ 5 Q 0 o . p. s. .-tpne ne .LL_j : • j ;; j 1° ,: i'll;: v-j-t’ :|^ I- I ;!-r. :^: ^ 4 j i ; |: J8; .J' 1::.J!.\ .• J.2 9 l : ,i£!.l. -i .. ;_■___: < j y ’ \ ._•|!j;j; j .!J '.:,; J :;! ■;/! 1 ' \-J1.7:-;■ !Sv 7:;•;[,!• , . ■ ! ! i®.. i-> ^ L :;'' 1 '-5:1 ''■■ ■-’■•! j ' I , ! 7 7 . ; y :'j J * re rP>*ri5:i p' r- ”! i“ i ’ 1 ^.©Kt ■ : ‘ " ;r j ;ir ;ij!:. j (O ’ 1 ■ ■'. i ! ;-iH ©-; I M -A ,-T;77!-7j:;^4ij^r:ux;a4 ion:;!!’ fc:!:7fe;i;7!7;7:;!7 :^ r r:-4n ]!: 4 ; / ;r ; ini:' rmr r:i:ri77|-i n ^v:7i7T; i -; • 1 ' : ■! i : ! ! . ,•■(••> ;!( ri ■ / ;!: [-{•!,;;; la I. Ai. j ~1.-J;. '..L l cc J .cjr^r.‘J;::I : 5 j A z dr . : ..... 1. u ! *.‘M-r <-Fu ci;.' (• {j!: :.!:' r • ! t . r* -yf.. S + -.-1 - ^ V " •i ■ 1 i-i1■" ■' rtiil'j.jucl-r:; : i d u l y .; h ir " i ;;i I-'. lic-PTj’’^n"rn^fcj;^^rvvn jm r vl- f-n ■ i pt j i;

• :; ;; j H t ' ' • - -1 > I ■ ’ C t ‘-| : t r ■-• •;•: i i .-i-f-i •-•>■>: I •-.-H i : ; r-| ,

■j:! I ■! 11 ||p c ‘-I | ijcjjljj-'-i ; ;|' 4 ' 1 ’ , i r ..l*"-1. . : : 1' : l:.

• i ■ ' {_ 1 f- ’ . < ; i ’ • ; • ■ ;-* •' t ! ■* : ! // ••• • .' JI . ; i :.‘l -.i..,. .' p

j i :-l t . r|.;.p .; •.x.fip* tl r,j j*7i ■,' “^1. 'i !v i;: . ■ ; r rf -ra-. ; (-■ ,-f-i ' - 1 |-'r ', ;•;! i\; f -1 .p, i J r |'-.' !'.’ >:' = j .'.'; • .’i-; • ; 1 -StJ m Jj+H-lltei J e JS f J;i J J t J •!!;a i;i:i.ii7 ; Jilmi 1 ’:i:ti;-'!■ i!! >7(1 Hi :#*?., I J , I

H r j r ;■ j ’ i.-i i I I ; !.! : 1 ; i ;.j !:i';.i-r ( m m i ( ;th p rii:f r ■ T::,.;: j 0 M 1':a--7rcTtTrMT:7r7:7-rj:H{^J]Tv;; :ccJ[JT:n--. 77 7. ;.y. 1i ! |‘ :! I [[>1: ‘ ’ f i"-'J' 'ii I -1 ai ! j: ’Ij tH liJ : u\ V, !\fd ; 1!' i ■; jri I i ’ ■ I •:r T T - tV! j .! ■ ! . - t : I m i .. I . ]' :■■ I • M ' 1 ; P ■ ■: ■!■• ■ ' ■ !------;— I------'— ^

Pa.iJf.-t1 ;• til' • 71: i : 71 rrp-i" 14I n ■ -J ■ :rrH-*rq:‘3i r rq.n j p..: pr. ;-r,-.rrv;yj' ■ -.:y. t: ;; ;.t'7'7'‘; .' . . p- Tcl-l'!' -.1

^ P T ^ P i - n ^ i-i-"!:;:!-1 i i ’ 4 ^ !: J I J ] . i i '' • . • I - ■ - ' ■i .-t.i..; - •' . .. ■ • i ; ' , . 1 1 I I .1.1 : . I .■. 1 1 I : . , ; . ■ : ' . : . i . .. : ... ,.!■ -RSiL^TlONSHIF , J - . - : J '11'1 : : 'MT,,n!r,>”SN ::THB I£EAp 8C0PE3 OF: ^HE'.PpREi-^OKn; TpST' I:.; ■:.■;i'! .'i i '... :: h i^nsgaR^^^s^f^EED m ■:j*!-■■'.;:::;|-*t;\

J 7 ; :j c ;; j J- a ljiU a y t; , 7 a c Hti . i ; J j - i^i h Jh : r 71.1;-7 (;: 1! 4 i; -7 y.i uJiaJt a -77 $ 741 -J J[ f i i y ' 1 i ■ !! i '■ < ;•; (< .1 i ;-*'•■ ! j 1 *: I • 1'- ' ■ 1 i ..;..* v.:;u * . j i ;-. ’ , . A : ; j i . ! •.; s r 7 1, i< • t ■. : : 1 i - U t i ’rf ] - 7 i ! A } I * I . i r— r'-t-r+ f fj :i.: jt:;N j!;:-i-j;jcJiiir-:

■ V- l :.. .'.:..'. i. Po.'t-zbo g. thf; h. CfU.i-. cc.. roj.t'MUur. onto. 85

13 show the mean scores for each frequency of the pure-tone scores for the better ear in seven levels of scores for the single-tone and white-noise pulse-type tests. The tytest was used to test the significance of differences between some of the means. The single-tone pulse-type test and the

500 c.p.s. frequency of the pure-tone test were significant­ ly different at the one per cent level of confidence between the score level of 10 and the score level of 2-1-0 and be­ tween the score level of 10 and the score level of 4-3. This would indicate that other levels of scores associated with the single-tone test were not differentiated by the pure-tone scores. Generally speaking, the same is true for the white-noise category of the tests. The significant differences between the means were between the high and low scores of the pulse-type test. Results of the tytests are summarized in Table XX. In summarizing the results of the analyses, the R-ratios of the single-tone pulse-type test and the fre­ quencies of the pure-tone test for the better ear were sig­ nificant only for the 500 c.p.s. frequency. These results differ from those obtained in similar analyses when the single-tone pulse-type test was administered monaurally. A possible reason for this difference is that it has been shown in previous studies of the pulse-type test that there is an increase in the number of correct responses on TABLE XX MEAN SCORES OF SEVEN LEVELS OF SCORES FOR THE SINGLE-TONE PULSE-TYPE AND WHITE-NOISE PULSE-TYPE TEST (BINAURAL) AND PURE-TONE TEST SCORES FOR THE BETTER EAR.

Better Ear Levels of1 Scores 10 9 S 7 6-5 4-3 _ 2-1-0 5 Single-tone pulse-type test 500 c.p.s. 1.90 2.22 2.88 2.23 3.69 8.09 16.78 1,000 c.p.s. 18.33 21.22 19.06 20.54 24.75 25.91 30.78 2,000 c.p.s. S. 90 14.89 12.75 4.85 14.63 19.09 19. ;i 4,000 c.p.s. 24.29 41.22 23.50 22.77 30.94 30.64 45.22 White-noise pulse-type test 500 c.p.s. 1.67 3.57 1.45 3.12 7.40 4.20 13.00 1,000 c.p.s. 19.00 19.57 18.10 18.88 22.20 26.40 38.55 2,000 c.p.s. 8.53 7.71 7.10 4.12 9.35 22.00 35.00 4,000 c.p.s. 23.27 19.29 18.90 32.76 28.20 26.20 61.63

Results of t-tests for vmite-noise test t value

Single-tone test and 5001 c.p.s. pure-tone t value and 2,000 c.p.s> • Columns 10 and 2-1-0 4.82* Columns 10 and 2-1-0 2.58 Columns 10 and 4-3 3.22* Columns 10 and 4-3 1.51 Columns 10 and 6-5 1.21 Columns 7 and 2:-l-0 3.54* White--noise test and 50C1 c.p.s. White-noise test Columns 10 and 2-1-0 9.94* and 4»000 c.p.s■ • Columns 10 and 4-3 1.51 Columns 10 and 2-1-0 5.04* Columns 10 and 6-5 2.56 Columns 10 and 4-3 .29 White'-noise test and 1,000 c.p. s. Columns 8 and 7 2.47 Columns 10 and 2-1-0 3.60* Columns 10 and 4-3 1.36 ^Significant at the 1% level of confidence. repeated trials. The F-ratios of the White-noise pulse-type test and the frequencies of the pure-tone test for the better ear were significant at the one per cent level of confidence. However, results of tytests for significance of difference between the means indicate that the significant differences were between the extreme categories of the test. It might also be said that although the tests fail to differentiate between subjects with good hearing and ones with poor hear­ ing, they do "fail" cases with poor hearing for pure tones; they also "fail" some cases with good hearing*

Hypothesis VIII The eighth hypothesis was, "scores of the single-tone pulse-type and white-noise pulse-type test (binaural) and scores of the speech reception test grouped according to two categories are unrelated as measures of hearing acuity. " Eighty-five of the 119 subjects were used in the analyses. Scores for both tests were separated into two groups as near the median as feasible so that the scores of the speech-reception test were classified into groups as lS-and-below and 19-and-above. The single-tone and white- noise pulse-type tests were categorized as seven-and-below and eight-and-above, The following example illustrates the classifications in a contingency table. 88 Speech-Reception Test 18^-below 19-above 7 -below 21 ".. 1 28 Single-Tone Test 49 (24.76) (24.24)

27 19 8 -above 46 (23.24) (22.76)

48 47 95

(21-24^7 6 ) 2 (28-24.2 4 ) 2 (27-23.24) 2 (1 9-2 2 .7 6 ) 2 = 2 .3 8 24.7 6 24. 24 2 3 .2 4 2 2 .7 6

Tiie number of scores for each category of the tests was: Speech-Reception Test Speech-Reception Test 18-below 48 18-below 43 19-above 47 19-above 47 Single-Tone Test White-Noise Test 7 -below 49 7 -below 53 8 -above 46 8 -above 42

The Chi-square test of independence was used to determine the relationship of the two tests. The results are summar­ ized in Table XXI. In the analysis of the scores of the single-tone test and the speech-reception there was a signi­ ficant relationship between the 10 and 20 per cent levels of confidence. In the analysis of the white-noise test and the speech-reception test, there was a significant relationship at the one per cent level of confidence. The results show the same pattern of relationship as those of this pulse-type test and the pure-tone test. TABLE XXI CONTINGENCY TABLES FOR THE CHI-SQUARE TEST OF INDEPENDENCE OF SPEECH-RECEPTION SCORES AND THE SINGLE-TONE PULSE-TYPE AND WHITE-NOISE PULSE-TYPE TESTS (BINAURAL)

S R T S R T

ia-below 19 above 18-below 19 above 7-below 7-below 21 28 20 33 Single-tone 49 White-noise 53 test (24.76) (24.24) test (26.78) (26.22)

27 19 28 14 a-above 46 8-above 42 (23.24) (22,76) (21.22) (20.78)

4 a 47 95 48 47 95

X2 = 2 .3 a* X2 - 7 .85 **

*Significant (X ) between the **Significant (X ) at the 10 and 20fo levels of confidence. level of confidence. Bi-serial correlation was used for further evaluation of the data. Scores for the two tests were categorized in the same manner as for the Chi-square test of independence. This procedure yielded correlations of .06 for the single-tone test and the speech-reception test and .08 for the white-noise and speech-reception scores. These values were not statis­ tically significant. A further analysis was made between scores below seven on the single-tone and white-noise pulse-type tests and the speech-reception tests. There were two reasons for this analysis: (l) it was observed in previous analyses that seven appeared to be the point of greatest change among the means of this pulse-type test, and (2) it was desired to see the relationship of the relatively small number of cases within the lower categories of the pulse-type test with the speech reception scores. The Pearson product- moment correlation was used in the analyses of these scores.

The number of scores in these categories was 36. Results of the analyses revealed correlations of .22 (not signifi­ cant within the 5$ level of confidence) between the scores of the single-tone test and the speech reception test and •57 (significant at the one per cent level of confidence) between the white-noise test and the speech reception scores.

In summary, results of the analyses were similar to those derived from tests of Hypothesis VTI, that is, there was low relationship between the scores of the single-tone test and tiie speech-reception test and significant relation­ ship at the one per cent level of confidence between the white-noise test and the speech-reception test. In treating selected categories of the single-tone and white-noise pulse- type with the speech-reception scores, the same relationship was found.

Hypothesis IX The ninth hypothesis was "scores of the single-tone pulse-type and white-noise pulse-type test as retests

(binaural) and scores of the speech-reception test grouped according to two categories are unrelated as measures of hearing acuity. The retests of the pulse-type tests were given immediately after the first binaural tests. Scores of both tests were separated into two groups as near the median as feasible so that the scores of the speech-recep­ tion tests were classified into groups as 18-and-below and 19-and-above. The single-tone and white-noise pulse- type tests were categorized as 7-and-below and eight-and- above. Scores were arranged in contingency tables in the same manner as for the test of the eighth hypothesis. There were 95 scores in each test divided as follows:

Speech-Reception Test Speech-Reception Test 18-below 4® 18-below 48 19-above 47 19-above 47 Single-Tone Test White-noise Test 7 -below. 51 7-below 51 8-above 44 8-above 44 9 fr

TJie Ghi-square test of independence was used to determine the relationship of the two tests. Results of the Chi-square tests of independence are shown in Table XXII. Results of the analysis between scores of the single-tone test and the speech reception test was .10 which is statistically signifi­ cant at the 70-80 per cent level of confidence. Results of the analysis between scores of the white-noise test and the speech-reception test was 5*63 which shows relationship between the one and two per cent levels of confidence. Both of these results show lower relationship between scores of the two tests as retests than when they were first adminis­ tered binaurally. Reasons for these discrepancies are unknown. A further test was made between scores of the pulse- type tests which were below seven and the speech-reception test scores. The number of scores for this analysis was 30. The Pearson product-moment correlation was used to test the relationship of the scores. This comparison of the single­ tone test scores and the speech-reception scores yielded a coefficient of correlation of .35, and between the scores of the white-noise test and the speech reception test, .35. The values were not significant at the five per cent level of confidence. In summary, the relationship between scores of the speech-reception test and the single-tone tests was less TABLE 23XC

CONTINGENCY TABLES FOR THE CHI-SQUARE TEST OR INDEPENDENCE OF SPEECH-RECEPTION SCORES AND THE SINGLE-TONE PULSE-TYPE AND WHITE-NOISE PULSE-TYPE TEST (BINAURAL-RETEST)

SET S R T 18-below 7-below 7-below 25 26 20 31 Single-tone 51 51 test (25.77) (25.23) White-noise (25.77) (25.23) ' test

23 21 28 8-above 44 8-above 44 (22.23) (21.71) (22.23) (21.77)

4$ 47 95 48 47 95 2 X = .10* i 2 = 5.63**

*Significant (X ) between the **Significant (X ) between the 70-80$ level of confidence. 1 and 2$ lever of confidence.

vO 'to close -than the relationship between the multiple-tone and speech-reception test. The relationship of the white-noise test and the speech reception test was significant between the one and two per cent levels of confidence but still less than in the instances of the multiple-tone test. Reasons for these discrepancies are unknown.

PART II The multiple-tone pulse-type test was originally administered in uncontrolled noise conditions ranging from levels of 55 decibels to 65 decibels. In order to evaluate this test in conditions different from the previous evalua­ tions, a second experiment was necessary. Two portable sound-treated booths (Appendix A) were set up in a class­ room in the Department of Speech at The Ohio State Univer­ sity.1 A turntable - amplifier was connected to the pair i The sound-treated booths were designed and built by Maurice Whitlock, Technician in the Department of Speech. They were used originally in administering the OSU Test as part of the physical examinations for men during the University Orientation Week in September, 1950. Pour booths were built in which S persons were tested simultaneously. of Permoflux FDR3 earphones in each booth. Each booth con­ tained a pencil and a pad of recording blanks (Appendix D). Another turntable-amplifier with attenuator was set up in the classroom to be used for producing recorded white noise. The G-eneral Radio Sound Level Meter, Model 759» was used 9'{5 to measure six levels of noise inside the testing booths. The first level, which was the ambient noise level in the booths, was 55 decibels (0 scale-General Radio Sound Level

Meter). Levels of 60, 65, 70, 75, and 80 decibels of noise were obtained at will by use of the white noise recording. One hundred and forty-four students in elementary speech classes at the Ohio State University were tested in groups of four, with the OSU Test. Twenty-four subjects were tested for each noise level. The ear tested first in each test was controlled by the examiner. Each subject, who failed to make a perfect score in either ear on the test was given a pure tone audiometric test for the 500, 1,000, 2,000, and 4»000 cycle frequencies immediately after the test. In order to analyze the data obtained it was neces­ sary to conduct a test for linearity of means based on 2 independent samples. Scores were arranged in six columns _ E. F. Linquist, "Goodness of Fit of Trend Curves and Significance of Trend Differences,” Psychometrika, 12: case 2, 1947« according to the noise levels in which the scores were obtained. Table XXIII shows the mean scores for each level of noise for both ears. The F-ratio for the left ear was

♦024 and for the right ear was .019, neither of which justifies rejecting an hypothesis of non-linearity. 96 TABLE 2X1II MEAN SCORES OE THE MULTIPLE-TONE PULSE-TYPE TEST FOR BOTH EARS IN SIX LEVELS OF NOISE.

Ear Noise Level Mean Score

Left 55 db 5.00 60 db 4.75 65 db 4.75 70 db 3.S3 75 db 3.67 SO db 2.13 Right 55 db 4.96 60 db 4* S8 65 db 4.79 70 db 4.12 75 db 3.45 80 db 2.50

Lines of best fit to represent the data associated with the two ears were determined by the method of least squares. The percentage of correct scores for each level of noise for each ear was plotted on graphs together with the related lines of best fit (Figures 14 and 15)• About 85$ correct scores were obtained in noise levels as high as 65 db. With higher noise levels the percentage of correct responses dropped to about 40$- Based on these results it would not be advisable to administer the multiple-tone pulse-type test in a noise level greater

than 65 db inside the testing booths. ‘■vuo ••simwn'io.i ‘ i-.-rt- i-U• in.-.,- ■ jj-jfi-M’tjH;1 rij.liif '-ft J-

L j-..!. ft : ft' ft-: ■ 11 ':i-. ft'-: ft:;;!: ft i1:ft I:ft p';' ft ft.aft ft" --ftftft. ft i ft ift fti I! ift'l • ' ■ .■! l- ; I-;--/,:.-; .. i =-| :■• r!--;-"-.; ■:JprTt-;-'-ssEnL-©3iiifl[-; Vji:: vv

•;; -;ft {. «K>/p©^p':2 0 0 b:‘r Pj p P l T ; :4 ;iftft r:rh;rn4tn;t.r-1Trfix, ’ f : ft ; ftyLft; ;.f, !■:•: "ft; ft; t ftftjft ft i'fti'fti ft a f t • Hf-i-i i'ft !;ft:-ftfftlftf; |jia [i, ,j;: j: ii ■ i ilftI;: ■P|.i|!:'I R-^idgjjj iiQjiii : ;:j 1^.fiiJ+iJJ: I fi ff j. R-iq.'.ixLtlpH! };rtB

ri:',Hrr:T®^rrfuTi;:!T i;:.iT 7ri?F ;T H T T i'nr^ Rtteiplu . . .1 ! a i ' I’fttil-rft ia! rttlf; ■Tf:? W M M r - L^'^h [;!.:: ^ ^' * :V ’ i:: ^ j i l’ - ' ; -Ivi >y ii rl t-fPf] f H - a ,.u ■j f; i i.j.l.i j;.fi.j.r !.ii L! • • i- , * ,1 .. , ,' : 1 ; . ; r. r < I , ■ ! : ! 1 .. ■ : \.\ t . f.,1 i f i_f. , ^3 ...; iT ■Bife riTftriOTiftrtft-fth-ftl -!tt1 :rjj' fm'itl-d mTMftftkuPftif >•» -. • I - . • * • l • ; j | . x i i-.i •-• ' - • • ■ ' . - I j f. | « I , ^ j. - v-|-. , T _CTr - J.j f t . f i-f ■ •; ■ ■- s:: 1■!:1 !■:-1 !:■! '■■; •.1 ■■.1 1 ‘ ■■:1 !■; ■:: :-■ .■.! 1:• ,■ ' \ > ■ i! • '-ix-jx-,1 <1 i U rjTtj. it ft 1 Vi.THrpt:- -a -I';.i; - {■■ 1 a :!,-.-! ; ,-: j ■ : • I :- •! UiLt. -j.!r If# .::.p .h4x TiftijsfriTrtnj-i 'M;rim fti •I ; • !- • * v‘> ; : > • f- i •; -• • : ' ; 1 i i i’-. iRRnh], i-ilii! 1 In.'-I-;. j l.:.i Hixri r' .£.j‘: M i-V- i; pi Hftgftftft I:.. Ift!a ■' V £ri.;;1 ■;.■■: 'P1 r!I;/: ■;:■■• a=, ■ . ,-i: ■ ‘t. \ f vqP.i.;; 1; ■ ! !;. f

'ftlr B: !: i|v;S pu.v*» s r ^ f t •. 1 ♦ i f>: I • i ■ i .''' ii! 'X;i:.Xr!:|liX;j 1: ::!l \ :': : 'Vs' Jyjr jX.!: xq.aqftta-v.. ft!!!;40f ftiPii ■ ; ; i • ^-; i j-v P^ktdr.H

nia-i'...-.. i.iTj rr.T., :ptft|hi|ift M Ifi’ii-‘lift; £h ’• > :-i{;i .ft ::.i-:iti !' iJ=fe UT^:p-- rfc; , ' r t1 M ; / h • '-r - a n a . ; r i Z r ■ q r r f t r r 1 W\n\l$ 1-llm.r p I1!’ ^ :; .4 iplftft.pi i m \ i i liiiip; ;4i4ftpb?ftfLiL ; SSftrft rftitrP .,. tftPTit: ■ ■ !■ ’ : i

n j f t e i f s f t j : • ^ ! . I .1 - y . !•)• 1 ^ I i- !-f i ■ " 1 L f j aft j ' 1 ! ' ( 1 • |i - , : If 1 - - 1 M . ft , - -I } ft ! |:;J 1 Eft1 ■ ftj-ftbii P f tf t''' ft -ftlift V;t : --''ft vi fta j-Lt •■: i .... i...: r.T'.. r : ~ n ; fiT- '...rj n .. t XT:.*; a :, \ ft! ft i ’1 [ ", .*j ■ 'ix; |. ; ;.* ft.!:; M] i i.. i!!. ■ , j 1 •■ -I • ; :■■• I : i r -r» \\i • t- ' : j'! f •, Jt 1 i '•« ; !aft ft-ftf v::a;.i i i._: ut a ‘ -.. r’a'1 ■ ft - - f. v v fta; ft ';: ■ a:.. :ftft.qj::ftft.q: ftvrSt.Kf!ft;x!\:vrf-ft;j.!r!v;ft.:ftftftit.j ft'-ft; ■ t )!>4'ftii/r!vi:,'ft:-ft;:

i• • ■ X: !i ; : , :■' :I . ■ ■ r , :• x‘ :! :M f•• tt r•• xt -je^ , n 4 *ib£r?‘' 5 e * z i T .! ^■*w1', : X p :.‘!T!!-!:ftx!anXaxifti:ja©!:.ft’T• 1 ■■•■• ; '■• : *; • •- > ,k‘ ■-- .l.x, i.. q a i ; ., n r ; : ■ ,i . . 1X , ;a:;:a;■!s ! i.',i i '■• r-,1 -l l.i'v.l'-'ft- r’y:. J ft—.;i-rr-.- ; .■ I;: r:!‘ v£i*'fiZ saw*5ft 1 >J.|^ ifcrri-.ift;-i- i•- •'.- rX'xii - -.! ft rrrt-'.i-j ; - ; •rfta:;i±rri;h-::ftft;i-fti'-tt-tH ft - ! --', J;' r. >r*•;v •• , I' <-■ i I;:' i j; 1 -f ■ j ft , r-• -i■ ■;

...... f t f t . ' f t ; ; . ! " ftlfttl ft ft! I j f t f t f t ft-L a ftft:4ftft-i:rI : ft 4 ' :f t 4 aftftft ix.;i ^ ; 1 - ft I ft| • I : ft;-; ..ftft! I : ft-ft j ftft:ftftft“ftft i£;■■-ftlft ft> ttftft ft ftftftift^ftaitliftftji ■ -. ' - j - r i f t i : ! - I , H • i 4 ‘ 1 ' - ■ : " i ■ ' • . J_i -'.ft t •>. J ; _ , i f t > f I - k ( - < 1 It ft-'l- l - f t • - r j l 1 •;•■■■ : 1 • i ‘. I r,::-] X i-1"1; I £ 4 [■■■, ■;-•;! ili'i.. q.; p i; ...... v - :! t; :\, ‘ * ' ■ ' - ] > t;. ‘.-j * f i j j r

IXuiMXLLpjx I i; ’Ml'

v ;!^ ;| ' :t ;; pp • - £ h § y p y :Mpixy I. - p :; : !4|.;: ■■: i !' KHi- ho ; .ssm ao s xlHoieh; jmeeo }m-x qfc&%rxitib ,1: i M u p I * x x ■:: ;1 ;xx ';:;; ; T " : :v:v‘ ' jyxxxPsTpx'x~jxrjrp:-XtX;,jXpvLpLXrpi : | f H ! X ' X ; : : i il :; X Ly ; i *x: ** xf xx-nT» ; ! x xxx;.>xx: x j-ix■■;;;p

X h 'rrtL “ r :: j }: ■,.! P!L.;l !.jiX |J .XX:LX ;. X X X; XI ", Li lXXXi:; i.LLLU- XXiXuiXlL; illMX jlX-i 1 [XpiLLXxjX XlP ,LX; Hi L1%;!-" litimjif!jt-i I I-:-! i ■L r H; /•iJ'r-H-1 i:it^H ! i • : L : .; >:;:T i i ! ■''j: i; -! ■ •; r ! X 1:, i.i:'I ■;;: | ; 1 >Hi j v!X X ;: -:1;-X fiL-H-HvHrttiL i f f ^ 1- -p'- H f f i X X S i S WiFiff^rritX j, L-L.. .;,{»! ' \i Y ;-!■.!-£:: ;■• • .r : ►• i' *• ‘i'-l r;* ..r - I ‘-t-1 t-r | j. 1L 1 ■' I*; 1 } Xt * 7 ; i ■ -r, Ti -' • ' ' ■ I;v it! ; L j j ; . j j ’ 1 ! ri ‘ I • i \ i -; - 1 - • ’ J •• 1! ■ :.r: -.1.j . . ^ u j 5.. HI l. i ■;’•LJ}f i. •:, 1 ! • ‘ I * r : • !: • 1 :» P: • 1 • :;.v : -x: !-;.r, l;-j ; ‘ mT!Xp-f-■;b - !LX Mx It -X: , ■ ■ i ■ ■ -: i : !-.i! - -s •• A , - j ; L j..l; L L ^ r n x v ; ; ix;p M , 1 l rxxx dxr.it ’ ■ ■ . :\ j ;:X : X j T ^ n 7::IX 'x.x;-Xr: - >: ] :-^xJ ;■ -TxjF:tu I : I : ■ 'J® ,: •: rd\., "i I • • I » * M - .r., L-i-Li;: : .X.:.:XL !X. .. :. ..X\ : .X:.j.LX.!X!X:X.X..J;i.;,.h ji:.!.y.: 0^r«;XX--p:Li r; j;:!■.;■! X |r >■;X : | X :; ) r ' :■^L 'A . |i jjv)'^;:X r | L ‘-;JtX X 4 fX i jii] x |-|f;'i -xx , P -i>. x-Px *'.**”■ --1 -*-«•, . - 1 ■ L 'Y,X ^-T Lf.‘.X _1 rX ' 7‘TVri'’ i ' i . ’.'V i '1';:.. -''1 Yi: L ■; r ^ M i'! :'t Vi i ■ ^ ^ i T: xl^lix"'-:- .x i •x . .O i ..'X. : ij !'•. wO r,I: r; - X : . J !X®lp|XIE:! ^ V iildXlilSSiXX :-X|Xc5'! X :.X ihlLTLLrX'n:.!^ :■!■■■ iL- XKvu^U'xlXX i j L !.. i r; ' ili, -.:! t X :; ; ; I -; i , ^ ,: *i I : X'!X-! ! 1 ‘:HU-j . f : p X-fX ; j ■ ;;i; - \ , < : - \ ; X LL: .v * X ifff b l i1:1 . X ; !'! j;'• .1 • Li/;.ri/ f .Mi . :. r. i ;^11 j ; ;■i \; \ ! r;■., !,.;:1; ; . ;;; j . * , \ , i- ;. '.M'." tp..i I ' , I t... ; L - X i X t t i t’-i x :, .XX; :p r:'L -yxx'] 1 !; ’'; ; : I.i !..‘.^j:r1TL|ni:i b.rt.; ; . - j •„!-•• ];■ ' ;Xjx::.!i;:: fI?- : l l}': J : XliiXSPliilXX L±u.ci IJ. |I. ' t I ;| Ii.| I t.X, , 1 :; j, r:; . •f * , ij >: L J H-: r > r '< ':V i L i J 1 1 M 0 ■ r; F- v-r • • ' : ' i x-:: . u ; . ' ... i -i+ - p vj r; I: ;1 i i:i. -xfxxii-yx, ■ - i, I X ! !v: ' I '...I'..-; ; s ; X ; 1 X ' r i X'" r l 'r *r ^ 1 y*' i ^ 6 X ;XX!XpL.i'X |X ';rX T:|X rX -; •rx x h ^ x ix X rfr!"'H:X'-f " "X'X' • :,! ■■:.'■■•.: i \ r,~:i ij f ; ‘:i.lJXi * j . ;. . •. -■.-.XX : !i\;-X.XXir4XiXX XX.XX-:iXX pP^XpXX'XX- Si , -Ml X IX. X :: xx Lx r :.(; \X...xXi;.X:X: : , jXi I’!.: 'I-ArtT ’ X L X X >-x ' 1 J Xx:]xxnx'L-----'Lx:L-x*c^':=xwxx;... -'PX-. ‘“xx'r'p'x 'X r YpixhxTXxrx 9®^';rnx‘x x LFTX xXxXiiirLXfLr,'■ ri r j" . f :X;X i j■ X X; X i L ; j :';'X "X |XX-X. TX' /• •XIX^:'.;X XX • X • X X^ X 1 j -X ?' 1^' j ‘X ':V 1 X . •;j r: • j r! ^: ■-X iX -XX‘ x X-|1 ' X X' ‘ i-: x i • • ■ ; X'X— XXJXpXV;'f|X 'X:r:’! : X;’X:T;|X■jX ‘X‘i ' " X ':XX"rrX‘ X ;X":'X: X ‘X” 'r ... ‘ ij,:LdJ.- : ; ■ J: - y ’ ru:;;rr.■ JX.::.H: : 1 \'L!.,:d:' . t . d;1 !• !.!:■/::!dl[X ! ^ ' F u’:! -F iVi'd'X'F.jdFdi ;;Fd.:JXiii:Xind^ * * J • X ■ - i i . . .X j;: V- X■ ■■■ ■ :' ; X i X t ' • X-.: -X XX -i i -II .: ; "■ . X i, ' X : .; ! I ; • : X >. X ! . . iXX i r i ; ; ‘X /: | , : : ' ‘X>: ! . ‘‘X1 X- - I CHAPTER V CONCLUSIONS

This study was concerned with the evaluation of two hearing tests, the primary concern being their usefulness as screening tests of hearing acuity. The two tests were compared with two other tests which have been found to be reliable measures of hearing.

Nine hypotheses were tested, essentially these:

(l) The pure-tone test and the speech-reception test are unrelated as measures of hearing acuity, (2) on the basis of pure-tone scores for a given frequency for a particular ear, there is no difference in the means of the groups of scores on the multiple-tone pulse-type test, (3) on the basis of speech-reception scores, there is no difference in the means of scores grouped according to three categor­ ies, on the multiple-tone pulse-type test or on the basis of grouping the multiple-tone pulse-type test scores into two categories, (4) the original multiple-tone pulse-type test and the same test under laboratory conditions are un­ related as measures of hearing acuity, (5) the multiple- tone pulse-type test and retest under laboratory conditions are unrelated as measures of hearing acuity, (6) on the basis of pure-tone scores for a given frequency for a particular ear, there is no difference in the means of

99 100 scores grouped according to categories of* the single-tone pulse-type and white-noise pulse-type test for each ear, (7) on the basis of pure-tone scores for the better ear, there is no difference in the means of scores grouped according to categories of the single-tone pulse-type and white-noise pulse-type tests (binaural), (8) the single-tone pulse-type and white-noise pulse-type tests are unrelated to the speech-reception tests as measures of hearing acuity, (9) the retest of the single-tone pulse-type and white-noise pulse-type tests are unrelated to scores of the speech- reception test. Four hypotheses were not rejected. The fourth hypo­ thesis which compared the relationship of the original multiple-tone pulse-type test and the test under controlled conditions was not rejected. While there was no significant relationship between the scores for the left ear, there was significant relationship at the one per cent level of con­ fidence for the right ear. The reasons for this discrepancy are unknown, since both ears for each testing situation were presumably tested under the same conditions. It was felt that factors other than a hearing loss contributed to many of the zero scores on the original test, since these scores were not duplicated on the test under laboratory conditions. For this reason another analysis was made in which the zero scores of the original test were omitted. The tests then showed a significant relationship. The differences in 101 scores for the ears of the original test can only be explained that by chance there may have been a difference in earphones for the different ears and that by chance the same earphones tested the same corresponding ears for most of the cases. The seventh hypothesis was rejected in part. The hypothesis tested was that on the basis of pure-tone scores there is no difference in the means of scores grouped accord­ ing to categories of the single-tone pulse-type and white- noise pulse-type tests (binaural). Results of the analyses revealed no significant relationship between the single-tone pulse-type test and the 1,000, 2,000, and l+t000 c.p.s. tones of the pure-tone test. There was significant relationship between the 500 c.p.s. tone of the pulse-type test and the pure-tone test. A possible explanation for this is that it has been shown by previous tests of the pulse-type test that there is a considerable change in the correct number of responses in repeated applications of the test to the same subjects. Since the test given monaurally did show a sig­ nificant relationship to the pure-tone test, and the binaural test, which was always given first in the series of pulse-type tests, did not, this seems to be the most logical explanation of the results. The difference in means between the white-noise pulse-type test and the pure-tone test was significant at the one per cent level of confidence. Reason for the differences in this test and the single-tone test are hot known. 102

The eighth hypothesis was that the single-tone pulse- type and white-noise pulse-type tests were unrelated to the speeoh-reoeption test as measures of hearing acuity. It was rejected in so far as it applied to the ear (not right ear). There was poor relationship (between the 10 and 20 per cent levels of confidence) between the single-tone pulse-type test (binaural) and the speech reception test. Possibly the same explanation for these results can be made as for those of the seventh hypothesis. The white-noise pulse-type test did show significant relationship with the speech reception test. The ninth hypothesis was also rejected in part. This hypothesis was identical to the eighth except for the fact that the pulse-type test was a retest. Again the single­ tone pulse-type test showed no significant relationship to the speech-reception test. In summary, the following conclusions can be made: 1. The hypotheses that there is no difference between the means of the multiple-tone pulse-type test scores as measured by the pure-tone and speech-reception test were rejected. Prom the analyses made, the multiple-tone pulse- type test under controlled conditions is a reliable measure of hearing acuity. 2. Results of the analyses made of the multiple-tone pulse- type test in six levels of noise indicate that an average of about 85 per cent responses can be obtained on the multiple-tone test in levels as high as 65 db inside the testing booths.

3 . There was significant relationship between the single­ tone pulse-type and the white-noise pulse-type tests as given monaurally and the speech reception-tests and the pure-tone tests. It is not known whether this would have been true had the pulse-type test (monaural) been given first in the series of pulse-type tests.

During the course of the study several possibilities for future research were indicated. They were: 1. The multiple-tone type-test needs further study in the type of situation in which it was originally given. 2. The single-tone and white-noise pulse-type tests need further study in the attempt to rule out any learning factor that may be contributing to errors on the test. 3. The efficiency of other pulse-type hearing tests may be examined as reliable screening tests of hearing. BIBLIOGRAPHY

Beasley, Willis 0., "Correlation Between Hearing Loss Measurements by Air Conduction on Eight Tones," Journal of the Acoustical Society of America, 12:104, July, 194*3. Bekesy, George Von, "The Early History of Hearing-Obser- yations and Theories," J ournal of the Acoustical Society of America, 20:727-48, November"! 194^* Breakey, Margaret and Hallowell Davis, "Comparisons of Thresholds for Speech: Word and Sentence Tests; Receiver vs Field, and Monaural vs Binaural Listening," Laryngoscope, 59:236-50, March, 1949* Bunch, Cordia C. , Clinical Audiometry, St. Louis: C. V. Mosby Co., 1943* 186 pp. _____ , "History of the Development of Audiometry," Laryngoscope, 51:1100, December, 1941* Carhart, Raymond C., "Monitored Live Voice as a Test of Auditory Acuity," Journal of the Acoustical Society of America, 17:339-49, April, 1946. ______, "Speech Reception in Relation to the Pattern of Pure Tone Loss," Journal of Speech and Hearing Disorders. 11:97-108, June, 1946. Carrell, James and G. J. Gormley, "A Critical Review of Literature on the Validity and Reliability of the Audiogram," Speech Monographs, 13:72, 1946. Ghesire, L . , M. Saffir, and L. Thurstone, Computing Diagrams for the Tetrachoric Correlation Coeffi­ cient, Chicago; The University of Chicago Bookstore, T7JTT 59 pp. Dahl, L . A ., Public School Audiometry: Principles and Methods, Danville, Illinois: Interstate Publishers, 1949. 290 pp. Davis, Hallowell, editor, Hearing and Deafness: A Guide for Laymen, New Y o r k : Murray rtill Books, 1947. 496 pp. Davis, Hallowell, et al, "The Selection of Hearing Aids," Laryngoscope, 56:139, March-April, 1946.

104 105 BIBLIOGRAPHY (Cont *d.)

Dickson, E. D. , et al, "A New Method of Testing the Hearing Efficiency of Aviation Cadets,” Journal of Laryn­ gology and Otology. 61:139, March 1946. Egan, James P., "Articulation Testing Methods II,” Research on Sound Control, Psycho-Acoustic Laboratory, Harvard University OSRD Report 3602, ^ro.jeot NA-108, 5§4 November 1, 1944. Fletcher, Harvey, Speech and Hearing, New York: D. Van Nostrand Co"., Inc., 1929. 331 pp. Fowler, Edward P., Sr., "Is The Threshold Audiogram Suffi­ cient for Determining Hearing Capacity?" Journal of the Acoustical Society of America, 15:60, July, 1943. Gardner, M. B. , "A Pulse-Tone Technique for Audiometric Threshold Measurements,” Journal of Acoustical Society of America. 19:592-99, July, 1947* Goldman, Joseph L., "A Comparative Study of Whisper Tests and Audiograms," Laryngoscope, 54:559-72, October, 1944. Goldstein, Max A. , Problems of the Deaf, St. Louis: Laryngoscope Press, 1933. 580 pp. "Functional Tests of Hearing," Oralism and Aurallsm, 3:1-20, 1924. Guilder, Ruth P., "Audiometric and Word Test Findings: Preliminary Report," Annals of Otology, Rhinology, and Laryngology. 52:25-33, 1943. Guilford, J. P . , Fundamental Statistics in Psychology and Education, Second Edition, New York: McGraw-Hill Co., Inc., 1950. 633 pp. Harris, J. D., "Group Audiometry," Journal of the Acousti­ cal Society of America. 17:73-6", July, 1945* ______, "Free Voice and Pure Tone Audiometer for Routine Testing of Auditory Acuity," Archives of Otolaryn­ gology, 44:452-67, October, 1946. Hirsh, I. J., "Clinical Application of Two Harvard Auditory Tests,"- Journal of Speech and Hearing Disorders, 12:151-58, June, 1947. 106 BIBLIOGRAPHY (ContT d.)

Hudgins, C. V., et al, "The Development of Recorded Auditory Tests for Measuring Hearing Loss for Speech," Laryngoscope, 57:57-80, January, 1947* Hughson, W . , and E. Thompson, "Correlation of Hearing Acuity for Speech with Discrete Frequency Audiograms," Archives of Otolaryngology, 36:526-40, October, 1942. Johnston, P. W. ,.. "The Massachusetts Hearing Test," J ournal of the Acoustical Society of America, 20:697-703, September, 1948* Kinney, Charles E., "Testing Hearing and Evaluation of Results in Mathematical Figures," West Virginia Medical Journal. 3 7 :448 -5 3 , October, 1941* Kopetsky, S. J,, Deafness, Tinnitus, and Vertigo, New York; Thomas Nelson and Sons, 194$. 314 PP* Leasure, J. K. , "Hearing Testing Cabinet," Annals of Otology, Rhinology. and Laryngology, 54:1^3-§T, 1945. Lifshitz, Samuel, "Fluctuations of the Hearing Threshold," Journal of the Acoustical Society of America. 11:118, July, 1939. Lindquist, E. F . , Statistical Analysis in Educational Research, New York: Houghton Mifflin Co., 194°* 266 pp. ______, "Goodness of Fit of Trend Curves and Significance of Trend Differences," Psychometrika, 12:3, June, 1947. Melis, S., "Individual Audiograms versus Mass Testing as a Means of Detecting Hard of Hearing," Journal of the International College of Surgeons, 5:498, November- December, 1942. McFarlan, Douglas, "Speech Hearing and Speech Interpretation Testing," Archives of Otology, 31:517-28, 1940. Miller, G. A., and W. G. Taylor, "The Perception of Repeated Bursts of Noise," Journal of the Acoustical Society of America, 20:171-82, March 1948. Newhart, H. , and S. N. Reger, "A Syllabus of Audiometric Precedures in the Administration of a Program for the Conservation of Hearing of School Children," Supplement to Transactions of American Academy of Opthalmology and Otolaryngology^ p . 16, October, 1944* 107

BIBLIOGRAPHY (Cont * d.)

Peatman, J. G. , Descriptive and Sampling Statistics, New York: Hamper and Brothers, 1947. 577 PP. Pollack, I., "Monaural and Binaural Threshold Sensitivity for Tones and for White Noise," Journal of the Acoustical Society of America, 20;52-57* January, 194^. rteger, S. N,, and A. A. Newby, "A Group Pure Tone Hearing Test," Journal of Speech and Hearing Disorders, 1 2 : 6l-r66, March, 1947. "Report of the Committee for the Consideration of Hearing Tests," Journal of Laryngology and Otology, 44:22-48, 1933. Senturia, B. H., and Alfred R. Thea, "Bone Conduction in Audiometry,"* Laryngoscope, 52:675-86, September, 1942. Snedecor, George W. , Statistical Methods, Fourth Edition, Ames, Iowa: The Iowa State College Press, 1946* 485 PP* Steer, M. D., and M, P. Doyne, "Studies in Speech Reception Testing," Journal of Speech and Hearing Disorders, 16:132-39, June, 1951. Steinberg, J. C., and M. B. Gardner, "On the Auditory Significance of the Term Hearing Loss," Journal of the Acoustical Society of America, 11:270-77, January, 19 40• Trowbridge, Barnard C,, "Correlation of Hearing Tests," Archives of Otolaryngology, 45:319-34, 1947* Watson, Leland A, , and Thomas Tolan, Hearing Tests and Hearing Instruments, Baltimore: The Williams and Wilkins Co., 1949. 597 PP. Witting, E. G., and W. Hughson, "Inherent Accuracy of a Series of Repeated Clinical Audiograms," Laryngo­ scope , 50:259-69, March 1940. APPENDIX A

Portable Sound-Treated Testing Booth - Eront View r u t * i 108 109 APPENDIX A {Cont»d. )

Portable Sound-Treated Testing Booths - Side View. P U te. £ 110 APPENDIX B

HAP-YAHD AUDITORY TEST '#1*1 Master Sheet F-197 • Record Se LIST 5a ' LIST 5b LIST 5c door.ra7 beehive ear thquake wo rkshop oatmeal grandson airplane scarecrow whit owash doormat c oughdrop outside play^round footstool birthday’" platform icebox toyshop churchbell lightbulb northwest ’ways Ide shotgun housework hardware jaclmif e stair.,iy horseshoe dugout iceberg eyebrow iceberg doorstep playmate ear thquake mushroom earthquake schoolboy oatneal headlight beehive railroad blackout blackboard greyhound airplane scarecrow a m cliair too tab rush. cowboy washboard playground jacknife shipwreck earOnun s idewalk beehive eyebrow workshop blackboard doormat airplane outside whitewash 1 Ightbulh birthday cookbook icebox sundown liardv;are pancahe backbone farewell schoolhouse toothbrusl mousetrap ’./askboard bloo dhound sundown shipwreck pancake s idev/alk farewell schoolhouse gr eyhound mousetrap scarecrow bloo dhound do o r ma c c owboy yardstick playgr ound ’woodchuck bi rthday cookbook wildcat padlock sunset blackout backbone gr eyhound lookout grandson armchair highway cowboy foots tool c oughdrop platform daylight toyshop churchbell do o rway northwest highway shotgun footstool ’ 'ildcat platform daylight daybreak churchbell lif eboat north’wes t padlock baseball s tarlight firefly schoolboy lookout eardrum rainbow workshop railroad grandson blackboard highway whi tewash playmate coughdrop mushroom daylight daybreak oatneal outside headlight lightbulb bas eball ways ide i C GO O ' C woodchuck hardware cookbook s tairway sundovm sunset lifeboat backbone padlock schooIhouse blackout firefly hotdog lookout s tarlight armchair doorstep wayside schoolboy rainbow housework railroad ho tdog s tairway washboard dugout jaclmif e yardstick horseshoe s idewalk pancake ey eb row f arewell doors tep mousetrap toyshop bloo dhound toothbrush yardstick shipwreck sho bgun mti shro on ’wildcat woodchuck daybreak suns et headlight housework bas eball lifeboat hotdog f irefly dugout do o r1' J£7j s tarlight horseshoe Iceberg rainbow playmate F— 197 Record Set Maico yUg6 0 LIST 9c LIST 9d grandson oatmeal out si cl e dugout highway c oughdrop daylight toyshop lighbulb icebox hardware hous ework yards t id sho tram wildcat ho t do g dugout iceberg do o ma y playmate ear thquake mushroom oatmeal daybreak beehive headlight bas eball wo rkshop scarecrov; airplane whitewash doormat jacknife p lay gr ound b irthday horseshoe eyehrov/ uorkshop doors t ep grands on whi tei/ash lightbulb c oughdrop v/ayside pancake liarckare s tai rway farewell mousetrap uashb o ard bloo cLhound Jaclmif e s Idewalk farewell eyebrov/ too thbrusl bloo dhound doormat shipwreck outside b i r tli da;' cookbook icebox sundown backbone greyhound schoolhouse scarecrow C O W O oy foots tool p lay ground platform do o r way churebb ell northwest woodchuck platform ^ 'llclcat sunset toyshop pa d lock north/est shotgun blackout eardrum lookout armchair beehive blackboard highway airplane foo tstool dap light day b real:: churchb el1 lif eboat has ehall wayside firefly hous ework s tnirwny sundovm floodlight pancake scaoolhouse blackout mous e t-rap gr eyhound armchair schoolboy cowboy eardrum railroad ho tdog blackboard s tarlight " a r c ’s tick ho rseshoe rainbow iceberg doors tep toothbrush earthquake washboard shipwreck wo o dchuck sidewalk cookbook sunset lifeboat backbone pa d lock fIrefly s tarlight lookout schoolboy raintow railroad playmate mushroom 111 APPENDIX C

Multiple Tone Pulse-Type Test (As Recorded) This is a hearing test. You will hear some tones or pulses like these. (One tone each for the frequencies 500, 1,000, 2,000, 4,000 c.p.s. were given at a level approximately 35 db above average threshold (reference o level .0002 dynes/cm. ). However, the tones you hear next will be very faint and hard to hear. Write the total num­ ber of tones you hear for each ear in the proper space on the blank before you. Here are the tones for one ear. (Five tones were then given at a 15 db level (reference level .0002 dynes/cm.^), one each for the 500, 1,000 and 4.000 c.p.s. The 2,000 cycle tone was given twice.) Write the total number you heard on the blank before you. (Two second pause.) Here are the tones for the other ear. Are you ready? Here are the tones. (Five tones were given at the same level as for the previous five tones. The 500, 2,000, and 4,000 cycle tones were given once each. The 1.000 cycle tone was given twice.) Write the total number in the proper space on the pad. Remove the earphones and take the sheet from the pad. CG O O 4 © CQ U © © c* M) Fame ______Co 11. ege______o Last First 4

Left ear p. 'Total number of pulses heard) H © 4- a

g© « h)

Right ear w 'Total number of uulses heard) i 1-3

©

1-3 © © d-

H H PO 113 APPENDIX E Score Sheet for Single—Tone and White—Noise Pulse—Typ® Test.

.APPENDIX E Score Sheet for Pure-Tone Test and Speech-Reception Test. AUTOBIOGRAPHY

I, Thomas Brown Anderson, was born in Lancaster, Kentucky, May 30, 1916. I received my secondary education in the public schools of Lancaster, Kentucky. My under­ graduate training was obtained at Transylvania College, University of Kentucky, and Washington University, from which I received the Bachelor of Science degree in June, 1939* 1 received graduate training toward the Master's degree at Butler University from which I received the Master of Science degree in August, 1947. From September, 1947 to June, 1949, I was employed as Instructor (part time) in the Department of Speech at The Ohio State University. From June, 1949, to June, 1952, I was employed as Instruc­ tor in the Department of Speech at The Ohio State Univer­ sity. From March, 1952 to June, 1952 I was sponsored by the Ohio Department of Health as an Scholar in the Department of Speech at The Ohio State University. During the period of these three appointments, I completed the requirements for the Degree of Doctor of Philosophy.

115