A STUDY OP THE RELATIONSHIP BETWEEN MEASURES OP SPEECH RECEPTION AND MEASURES OP PROFICIENCY IN LANGUAGE

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

ETHEL POLADARE MUSSEN, B.A., A.M.

The Ohio State University 1954

Approved by:

Adviser Department of Speech ACKNOWLEDGEMENTS

Acknowledgement Is due Dr. John W. Black who directed and advised the author through the experimental stages and first literary efforts on the dissertation.

ii TABLE OP CONTENTS

CHAPTER PAGE I. INTRODUCTION...... 1 Introduction ...... 1 Purpose of the study .... 1 Hypotheses ...... 2 Definition of terras ...... 3 II. RELATED RESEARCH...... 4 Bell Telephone Laboratories" contributions .. 4 Methods of deducing "ability to hear speech" from audiograms ...... 6 The development of standardized speech recep­ tion tests...... 10 Correlation of speech reception tests with audiograms ..... 13 The use of speech reception tests in diagnosis and therapy ...... 21 Research on factors affecting -hearing for speech...... 27 Differences between monaural and binaural, thresholds 28 Frequency and intelligibility ...... 28 Intensity and intelligibility ...... 30 Individual differences in audition...... 30 H i CHAPTER PAGE III. PROCEDURE .... 35 Selection of subjects ...... 35 Language measures ...... 35 Equipment .... 40 Hearing measures .... 42 Presentation ..... 44 Scoring of tests ...... 46 •IV. RESULTS AND DISCUSSION ...... 48 Hypothesis I ...... 49 Hypothesis I I ...... 39 Hypothesis I I I ...... •...... 62 Hypothesis I V ...... 69 Multiple correlations...... 75 Discussion...... 79 Recommendations ...... 82 V. SUMMARY AND CONCLUSIONS ...... 84 Summary ...... 84 Conclusions ...... 85 BIBLIOGRAPHY ...... 87 APPENDIX A ...... 93 APPENDIX B ...... 95 APPENDIX C ...... 97 APPENDIX D ...... 99 lv CHAPTER PAGE

APPENDIX E ...... 101 APPENDIX F .... 106 APPENDIX G ...... 108 APPENDIX H ..... 112 APPENDIX I ...... 121

v LIST OP TABLES TABLE PAGE I Summary of Hearing Loss in Coded Scores, Total for Each Decile. Better Single Threshold, ’ EitheoFiEar ...... 52 II Summary of Hearing Loss in Coded Scores, Total for Each. Decile. Better EarThresholds ...... 53 III Summary of Hearing Loss In Coded Scores, Total for Each Decile. Total Thresholds, Both Ears. 54 IV Summary of Coefficients of Correlation Between Tests of Hearing for Speech and Pure-Tone Thresholds ...... 6l V Summary of Coefficients of Correlation Between Tests of Hearing for Speech and Language Ability .... 63 VI Summary of Total Scores Arranged by OSPE Decile ...... 74 VII Estimated Coefficients and Corresponding Standard Deviations and Ratios for Computing Multiple r ? s ...... 77 VIII Number of Male and Female Subjects for Each OSPE Decile...... 94 IX Individual Scores on Language and Hearing for Speech Tests ...... 113 X Subjects? Unconverted Letter-Guessing Scores Total of Ten Phrases Per Subject ...... 116 XI Individual Pure Tone Thresholds in Coded Scores ...... 118 XII Coefficients of Correlation, Means and Standard Deviations used in Multiple Correlations ...... 122 XIII Matrix and Inverse Matrix Used for Multiple Correlation ...... 123 XIV Prediction Equations Using Estimated Raw Score Coefficients ...... 124 vi LIST OF FIGURES

FIGURE PAGE 1. Block Diagram of Equipment Used to Deliver Speech Reception Tests ...... ^1 2. Block Diagram of Room Used in Experiment .... *f5 3. Illustration of Method of Recording and Coding Individual Audiograms ...... 50 Composite Audiogram for Each OSPE Decile .... 55 5. Range and Standard Deviation of Intelligence Quotients Computed from Wechsler-Bellevue Vocabulary for Each OSPE Decile ...... 66 6. Range and Standard Deviation of Letter- Guessing Total Z Scores for Each OSPE Decile ...... 68 7. Range and Standard Deviation of Speech Reception Thresholds for Each OSPE Decile ... 71 8. Range and Standard Deviation of PB Scores for Each OSPE Decile ...... 72 9. Range and Standard Deviation of Multiple- Choice Test Scores for Each OSPE Decile .... 73

vii CHAPTER I

INTRODUCTION

For the past thirty-five years, engineers, psycho­ logists, and clinicians have explored the relationships between perception of pure tones and of spoken signals. Research has indicated that relationships exist, but these are affected by age, intelligence, context, and still other, undefined factors. Ry means of pure tone audiometry, neural, cochlear, or conductive pathology of the ear can be described rather precisely. Audiograms may then be supple­ mented with tests of speech perception for a more complete diagnosis. As in a thorough pure tone audiometric examina­ tion, evaluation of hearing for speech involves several measures. Investigators have found that group performance on one type of test is predictable from performance on the other; individual performance is not. Prediction for the individual is the major clinical problem.

PURPOSE OF THE STUDY

The primary purpose of this study is to explore the relationship between verbal factors and performance on tests’ of hearing for speech. A prior study demonstrated that each of two speech reception tests could distinguish between sub­ jects with hearing loss and those without, both for grade

1 2 school and for college subjects.1 However, a number of

1 Ethel Foladare, An Experimental Study of a Recorded Multiple-Choice Test of Word Reception. Unpublished M. A. thesis. The Ohio State University, 1952. subjects with hearing loss for pure tones performed better than their normal-hearing peers; the reverse was also noted. In the youngest groups this was shown to correspond with per­ formance on written tests of "verbal intelligence." Similar records were not avaihble for the older students. The ques­ tion arises as to whether these data for college students would reveal the same relationships.

HYPOTHESES

Four general hypotheses were tested for a normal- hearing population. Stated in the null form, these were: 1. There is no significant relationship between threshold of hearing for the pure tones 500,1000,2000, and 4000 cps and three measures of hearing for speech: a. Speech reception threshold (SRT) in db b. Speech discrimination score (PB) in percent correct c. Response readiness (RR) score in number correct 2. There is no significant relationship among measures of hearing for speech.

3. There is no significant relationship among the measures of language ability. a. OSPE centile rank b. OSPE-RC (reading comprehension) centile rank c. Wechsler-Bellevue vocabulary (in IQ) d. Letter-Guessing scores 4. There is no significant relationship between the language measures and performance on tests of hearing for speech.

DEFINITION OF TERMS

Pure-tone Threshold is the sound pressure level (re audiometric zero) at which the subject just hears a given frequency. Speech Reception Threshold (SRT) refers to the level at which a subject is able to repeat correctly 50 percent of the spondaic words on the recorded Harvard Auditory List #14. Discrimination Score (or articulation score) is the percent of fifty monosyllabic words repeated correctly (recorded PB list #9). Response Readiness Score is the number of- correct choices made from a total of 76 mono-and dissyllabic words. This is a multiple-choice test.

Language Ability is measured here by performance on such verbal tests as vocabulary, reading comprehension, and ability to fill in mutilated words and phrases. CHAPTER II

RELATED RESEARCH

A. BELL TELEPHONE LABORATORY CONTRIBUTIONS

The rapid growth in electronics and the development of the telephone during the early decades of the Twentieth Century turned attention to the physical aspects of speech and hearing. The staff of Bell Telephone Research Labora­ tories related the design of telephone systems to the whole communication process from talker to listener. They inves­ tigated the fundamentals of speech and those variations which affected intelligibility or understanding by the listener. The scope of their investigations extended to normality and abnormality in both speech and hearing. The fundamental results and methods of experimental and mathe­ matical research were summarized once in 1929*^ and again in 1954.2

1 Harvey Fletcher, Speech and Hearing. New York: D. Van Nostrand, 1929. 2 , Speech and Hearing in Communica­ tion. New York: D. Van_Nostrand, 1954.

Members of the staff published prolifically during those twenty-five years. New data were presented one year to be interpreted again a decade later in light of subsequent studies with improved techniques. Interests ranged from 5 exploration of normal thresholds^***-*5 through intelligibil-

3 L. J. Sivian and S. D. White, "On Minimum Audible Sound Fields," JASA. 4 (1933), PP. 288-321. **■ H. Fletcher sand W. A. Munson, "Loudness, Its Definition, Measurement, and Calculation," JASA. 5 (1933),p. 82 ff. 5 w. A. Munson, "How Little We Hear," Bell Lab. Record. 21 (1943), P. 341. , .

ity^,7 and measurement of the speech s t i m u l u s . ® *9,10

H. Fletcher and J. C. Steinberg, "Articulation Test­ ing Methods," Bell System Technical Journal. 8 (1929), p. 8o6. 7 N. R. French and J. C. Steinberg, "Factors Governing the Intelligibility of Speech Sounds," JASA. 19 (1947), PP. 90-119. Q Homer Dudley, "The Carrier Nature of Speech," Bell System Technical Journal. (1940), p. 495. 9 H. K. Dunn and D. W. Farnsworth, "Exploration of Pressure Field Around the Human Head During Speech," JASA, 10 (1939), PP. 184-199. . . . H. K. Dunn and S. D. White, "Statistical Measure­ ments on Conversational Speech," JASA, 11 (1940). pp. 272- 288. "

T1 Shannon in 1949, introduced his theory of communication

11 Claude E. Shannon and Warren Weaver, The Mathemat­ ical Theory of Communication (Urbana: Unlversityof Illinois Press, 1949). which permitted all parts of the process to be manipulated in mathematical terms.- Bell and its subsidiary, Western Electric, evolved the first economical practical, and accurate American audiometer— the 2A— and a line of hearing aids. The staff dealt with theory of hearing,12 hearing loss,1^ and the

12 H. Fletcher, “A Space-Time Theory of Hearing," JASA. • 1 (1930), pp. 3H t314. Also in. Speech and Hearing in Communication. Chapter 14. ^3 j. c. Steinberg, H. C. Montgomery and M. B. Gardner, "Results of the World^s Fair Hearing Tests," Bell Sys. Tech. J.. 19 (1940), pp. 533-562. relationship between hearing for pure tones and speech.^ * 1 5

H. Fletcher, "Calculating Hearing Loss for Speech," JASA. 22 (1950), pp. 1-5. (Speech and Hearing in Communicar tion. Chapter 20.) -*•5 L. Watson and T. Tolan, Hearing Tests and Hearing Instruments. Baltimore: The Williams and Wilkins Company, 1949, P. 48.

B. MTHODS OF DEDUCING "ABILITY TO HEAR SPEECH" FROM AUDIOGRAMS

French and Steinberg1^ demonstrated that the essential

French and Steinberg, op. cit. frequencies for the'understanding of speech were those be­ tween 500 and 3000 cps. The "speech frequencies" which were checked as part of routine pure tone audiometry were the octaves 512, 1024, and 2048 cps. Four thousand and ninety- six was considered just outside the upper limit of frequen­ cies vital to speech perception. The pure tone audiogram showed by threshold measure­ ment what loss existed in the region from 500 to 3000 cps, which also was the area of greatest acuity. The Bell engineers at first regarded elevated thresholds as reduction of a total hearing range of 120 db in the vital region. They suggested a simple method of calculation of percentage loss: average the three significant thresholds and multiply the result by .8. Thus a 40 db loss was not 40 percent but 40/120 or 30 percent of “hearing loss for speech." "Per­ centage loss" was considered more desirable as a term for use by the courts and laymen than the unfamiliar "decibel." Although this particular method was satisfactory for des­ cribing moderate losses, a 100 db loss in the speech range is more Incapacitating than 80 percent indicates. In 1935 and 1936 Willis C. Beasley directed the National Public Health Survey of Hearing. In Bulletin #5"^

-*•7 Willis C. Beasley. National Health Survey: Hear­ ing Studies. Washington D.C., U.S. Public Health Service, 1936. Bulletin #5, Normal Hearing for Speech in Each Decade of Life."

he analyzed the pure tone threshold audiograms and indicated whether certain patterns of loss were related to hearing for speech. On the basis of French and Steinberg^s findings, he concluded, "A good audiometric index to the ability of an individual to hear speech sounds is obtained by taking the average hearing loss by air conduction on 1024 and 2048

cycles." In Bulletin #6,1® he assumed that the predominance of

^ Ibid. Bulletin No. 6. "Sex Differences and Age Variations.in Hearing Loss in Relation to Stage of Deafness." high frequency (above 1500 cps) losses in males and low fre­ quency (below 1500 cps) losses in females of the same age ranges demonstrates "the impossibility of improving their (males ?) ability to hear speech to an extent equivalent to that attained among females by uniform amplification of speech sounds." Reymert and Rotraan1^ investigated the sex differences

•*•9 m . l . Reymert and M. Rotman, "Auditory Changes in Children from Ages 10-18," J. Gen. Psych., 68 (1946), pp. 181-187. of boys and girls below eighteen years of age. They found that auditory acuity reaches its maximum at the ages from thirteen to fifteen. At pubescence boys are able to hear lows better and the highs less well than girls. The change, however, is in the boys, for the girls? audiograms are con­ stant throughout these ages. Although the acuity changes, the shape of the curve does not. Stevens and Davis^® plotted the hearing of the normal

20 S. S. Stevens and H. Davis, Hearing: Its Psycho­ logy and Physiology. New York, John Wiley and Sons, Inc. I938. Chapter 2. 9 human ear in difference limens for frequency and intensity. This led to calculation of relative values of each area of the audiogram, hased on "dimension in dl's." The speech frequency areas have a greater density of difference limens than other areas, but "these dimensions in themselves were not sufficient to take in all aspects of perception of speech."21

21 L A. Watson and T. Tolan, op. cit.

The Committee of Consultants on Audiometers and Hear­ ing Aids of the American Medical Association (P. Sabine, E. Fowler, and C. C. Bunch) by 1942 had investigated a num­ ber of suggestions for evaluating audiograms. Fowler22 and

22 E. P. Fowler, Sr., "A Simple Method of Measuring Percentage of Capacity for the Hearing of Speech," Arch Otolaryng. December, 1942. p. 874.

Sabine23 assigned percentage weights to frequencies from 512

23 p. e. Sabine, "On Estimating Percentage Loss of Useful Hearing," Trans. Amet Acad. 0.0.. March-April, 1942. to 4096, and ratios of 7 to 1 for importance of the better ear,' Additional studies by both men lead to Fowler^s 10 criticism of the method.2^>25*26 He pointed out that the

2^ Fowler, "Hearing Standards for Acceptance, Dis­ ability Rating for.Discharge in the Military Service and Industry," Laryng.. 51 (1941), PP. 937-946. 25 e. P. Fowler, Sr., "The Percentage of the Capacity to Hear Speech and Related Disabilities," Laryng.. 67 (194-7), pp. 103-113. 2^ Fowler, "A Simple Method of Measuring Percentage of Capacity for Hearing Speech," JASA. 13 (1942), p. 373. binaural relationships of 7:1 are not valid for all people. He attempted to include additional weights in his calcula­ tions for superiority of bone over air conduction, presence or absence of tinnitus, and degree of recruitment. Further modifications of the AMA percentage loss computation used different percentages, but the same 7:1 ratio. Other fac­ tors are noted separately on the audiogram form. Watson and Tolan27 charted decibel versus percentage

27 Watson and Tolan, op. cit., p. 57.

loss. The function Indicates that an average loss of 25 db or less has little effect on hearing for normal speech, whereas a 45 db average threshold equals a 60 percent loss, and 80 db is equivalent to 95 percent loss of usable hearing.

C. THE DEVELOPMENT OF STANDARDIZED SPEECH RECEPTION TESTS

It became clear to clinicians that the best estimate of hearing for speech could be obtained by using a speech rather than pure tone stimulus. One of the simplest, early tests of speech reception was the Western Electric 4-A, later 4-C, audiometer. This was not a true audiometer, but a phonograph with matched earphones suitable for group test­ ing. The recorded stimuli— the so-called "fading numbers"— consisted of a man?s voice and a woman's voice reading several series of two-digit combinations. Groups of numbers were attenuated in eleven 3 db steps. Its usefulness is limited by the small sampling of speech sounds, the preva­ lence of easily distinguished vowels and the narrow range of amplification. Bell Laboratories continued to develop tests from 1919 to 1937. Fletcher and Steinberg2® published their

2® Fletcher and Steinberg, "Articulation Testing Methods," loc. cit. principle methods of calculation together with the materials used. The latter consisted of two types of speech; nonsense syllables and sentences, which represented all the sounds of English. The sounds, syllables, or words recorded by the listener compared with those uttered by the speaker yielded a fraction of correct responses called the "articulation." These procedures were designed to test equipment and sys­ tems. The auditory acuity of the listeners was determined before testing thd most subjects had better than normal hearing. Listening performance improved with practice. 12 The material was not suited to general clinical testing as it presupposed at least fair educational level and a famil­ iarity with the New York vicinity.

Egan and Weiner2^ made up similar tests to be used

29 j. Egan, "Articulation Testing Methods," Laryng., 58 (1948), pp. 955-991. with Army communication equipment. They held that "speech sounds should represent conversational speech, should be as frequent as in normal speech for validity." The test items may be syllables, meaningful words, or meaningful phrases and sentences. Short words are missed more often than long ones, and in order to develop a discriminating test, they used monosyllabic words. The lists were composed so that they were of 1) equal average difficulty, 2 ) equal range of difficulty, 3 ) equal phonetic composition, 4) representative of English speech, 5 ) words in common usage. Twenty lists of 50 monosyllables met these criteria, although some question has been raised about the phonetic composition and familiarity of the words. The tests were easier than the Bell lists, but still compar­ atively difficult. For example, listeners who had eight days of practice showed an increase from a mean of 58 per­ cent to 78 percent correct. Repeating the test with new lists usually yields different scores, so that a mean of several tests is more reliable than any single list score. The phonetically balanced (PB) lists are in the same tradition as the Bell Labs lists in that they test systems rather than speakers or listeners. The score is considered an "articulation score." "Discrimination" scores measure listening ability. Concurrently with Egan's work at the Psychoacoustic Laboratory, Hudgins and others^0 developed another series of

3° C. V. Hudgins, I. Hawkins, J. E. Karlin and S. S. Stevens, "The Development of Recorded Auditory Tests for Measuring.Hearing Loss for Speech," Laryngoscope. 57 (19^7)# PP. 57-89. recorded auditory tests intended to measure hearing loss for speech. These stimuli were meant to reveal something about the listening process either in noisy conditions or with the presence of hearing loss. "The loss of hearing for speech can be measured in db in a manner similar to that used to determine the hearing loss for pure tones."31 The essential

31 Ibid. requirements are a) adequate test material, b) suitable equipment, c) an established normal threshold based upon a group of listeners with normal hearing. These test materials consist of words or short sen­ tences and are meeting the requirements of familiarity, phonetic dissimilarity, normal sampling of English speech sounds, and "homogeneity with respect to basic audibility." 14 Two lists of 42 dissyllabic words of equal stress (spondees) proved to have the greatest audibility. These were scrambled into six versions each, i.e., 12 forms. The threshold of hearing for speech is given in terms of attenuation in db below the standardizing voltage. For example, 100 db = 1 volt.100-70 = 30 db. The average thres­ hold is subtracted from that of the patient and the differ­ ence in db is the "hearing loss for speech." The normal 50 percent point occurs at around 23 db. (On the average, 6 db more (20) will yield scores of nearly 100 percent, minus 6 (17 ) will be near 0 percent— a 10 percent rise per db of amplification. Fifty percent represents the middle of the steepest part of the curve.) Hearing loss may be determined satisfactorily even though nothing is known of the actual physical intensities involved. The essential point "is to measure in db . . . the difference in intensity level at which speech samples are Just intelligible to normal and defective ears."

Harris^2 compared the two lists— monosyllables and

J. D. Harris, "Some Suggestions for Speech Recep­ tion Testing," Progress Report #2. 1948. U. S. Submarine Base, New London, Connecticut. spondees— and methods of delivering these stimuli. Although he concluded thfct monitored free voice delivery is superior to un-monitored, he warned that the use of devices tends to make the speaker feel that the words are equal in intelligi- 15 bllity. Increasing intensity level and limiting peak power level does not seem to affect intelligibility so much as the selection of the words. Carhart was among the first to put these two major tests into clinical practice. The lists were administered by monitored live voice. He concluded: Clinical observations have shown that the Harvard bi-syllabic word lists yield thres­ holds which are highly independent of intelli­ gence, language proficiency, or related factors. In other words, the ordinary variations of human ability do not seem to have an important effect on speech reception results, even when patients of low basic ability are being tested.33

33 Raymond B. Carhart, "Individual Differences in Hearing for Speech." Ann. 0. R. L. 55 (1946), pp. 233-67.

D. CORRELATION OP SPEECH RECEPTION TESTS WITH AUDIOGRAMS For the non-military clinician, the recorded test

slowly achieved favor. Werner M u e l l e r 3 4 outlined an

3^ W. Mueller, "A Clinical Examination of the Hard of Hearing," Ann. 0. R. L.. 51 (1942), pp. 56 ff.

examination which included pure tone and speech audiometry. He suggested that the percentage of words correctly repeated with adequate amplification should be over 90 percent. Performance on these tests should verify the audiogram. 16 Macfarlan35 stressed the necessity for testing speech recep-

35 Douglas Macfarlan, "Speech Hearing and Speech Interpretation Testing, " Arch. Otolaryng.. 31 (1940), PP. 517-528. tion as well as pure tones rather than accepting an average loss from the audiogram as a predictor of speech hearing.

In 1942, Hughson and T h o m p s o n ^ reported a study in

36 Wm. Hughson and Eva Thompson, "Correlation of Hearing Acuity for Speech with Discrete Frequency Audio­ grams," Arch. Otolaryng.. 36 (1942), pp. 526-540. which they sought to establish l) a normal threshold of hear­ ing for speech, and 2) a simple method of correlating audio­ grams and speech hearing disability. They concluded that it was possible to predict either threshold from the other. They recommended that hearing tests should be appli­ cable within reasonable limits to all age groups, all degrees of normal intellectual capacity and educational level. Their test did not distinguish between social or intellectual groups or between nerve and conductive hearing losses. Age was a factor only in regard to size of vocabu­ lary, since there was no need to read or write. The average normal threshold for sentences was about 10 db above the normal threshold for tone. Significant correlations appeared with pure tone thresholds from 512 to 2048 cps. 17 Carhart^? ran an extensive series of investigations

37 Raymond B. Carhart, "Monitored Live Voice as a Test of Auditory Acuity," JASA. 17 (1946), pp. 339“349. at Deshon General Hospital. In these he correlated pure tones with monitored live voice speech audiometry. Thres­ holds on each ear for the pure tones 512-4096 cps were computed as follows: 1) The "better ear" loss, i.e., the better threshold, at each frequency 512-2048, 2) The "bebfc single threshold" between 512 and 2048,' 3) The "better ear average loss" for the following: 256-4096, 512-2048, 1024-4096, 4) AMA computation (1942 method) for percent loss. The range of correlation coefficients was .55 to .69; all relationships between the two tests were of about the same magnitude. However, SRT was most highly related to the best single threshold between 512 and 2048, the better ear average for 512-2048, and the better ear loss for 1024. In general, the area between 1024 and the two adjacent octaves seems most vital to speech reception thresholds. Correspondence between SRT and hearing loss in db was checked by central tendency methods, i.e., means and standard deviation. He concludes that "other things being equal, the audiometric criterion which is most usefully related to speech reception is the one which is closest in its central tendency and variability." The audiometric measures with the closest correspond­ ence were 1) progressively greater loss for pure tones in the higher frequencies, 2) mean average in db for the better threshold from 512-2048 cps, or the better single threshold at 1024 cps. The best prediction from regression equations can be made for the average loss in db for the three fre­ quencies tested from 512 through 2048 cps. The correlation coefficient between this average and spondees was .75. Even this, however, has a large standard error of estimate. All three tests seem to measure common aspects of auditory acuity. Pure tones, however, depend more on the simple awareness of sound, speech more on instantaneous recognition and discrimination., Therefore, . . . auditory acuity must be a generalized capacity which is measureable in different ways. Speech reception threshold has the advantage over pure tones of being one step closer to highest socio-economic significance. Both combine to give a better clinical picture than either alone.38

38 n,l a .

Carhart39 also examined the problem of those patients

/

39 r . carhart, "Individual Differences in Hearing for Speech," Ann. O.R.L.. 55 (1946), pp. 223-267. who deviate markedly from the relationship of average "better ear" loss with speech reception loss. The coefficient of 19 correlation is .71. Standard error of estimate for predict­ ing pure tones is 14.4 db and for SRT 13.7 dt>. This is due to sharp individual discrepancies between the two criteria of auditory acuity, Carhart accounted for discrepancies by the character­ istics of the population tested: unfavorable auditory atten­ tion, limited language ability, inferior intelligence, neurological trauma, and psychogenic effects. Hearing for pure tones superior to that for speech could arise from any factors which interfere with integration of auditory pattern and language symbols. In the opposite direction, however, the pure tone loss cannot be accepted as representing the true organic damage since the act of repeating speech is more complicated than the act of recognizing presence of sound. Hence, one can rule out factors of limited language ability for intelligence. Psychological factors and fortuitous patterns of loss probably accounted for speech reception being superior to pure tone. Cases of high tone loss did show some systematic dis­ placement in the direction of better speech reception thres­ hold than pure tone average, indicating that high tone acuity is not vital to: hearing for speech. Also, subjects with recent losses of less than two years? duration, showed better hearing for speech, while speech reception for patients with losses of over two years? duration was either the same or worse. 20 To explore the relationship of speech reception and the pattern of pure tone loss, Carhart^0 divided the subjects

R. Carhart, "Speech Reception in Relation to Pattern of Pure Tone Loss." JSHD. 11 (1946), pp. 97~108. into five major types of audiometric curves. The spondees were administered binaurally. The author correlated speech reception threshold with the better ear average of audiometric testing of the fre­ quencies from 512 to 2048 cps. With one exception, all correlation coefficients were .71 or better, with a maximum of .87 for the group with a notch at or above 2048 cps. A poor correlation for Group 3 (marked high tone loss) emphasized the slight effect of poor thresholds at 4o6o cps or above upon speech reception threshold. Speech reception is apparently more dependent upon the average of 512-2048 cps than on pattern alone. Within groups, the difference scores between speech and pure tone thresholds were used to explore systematic differences between each audiometric contour and SRT. Re­ gardless of pattern, there occurred extreme individual variation in every group, including that with flat curves. The standard deviations for the groups ranged from 9.8 to 13.8 db. Patients with marked high tone loss had a mean SRT above that of their 512-2048 average, while the means of the other groups were equivalent to zero. 21 E. THE USE OP SPEECH RECEPTION TESTS IN DIAGNOSIS AND THERAPY

Once the speech test was established as a fairly reliable indicator of hearing handicaps, it was applied to therapy and fitting of hearing aids. Carhart was in charge of the Deshon rehabilitation program. In "Selection of Hearing Aids"^1 he stated that

^ R. B. Carhart, "Selection of Hearing Aids," Arch. Otolaryng., 44 (1947)# 1-18.

when there is a discrepancy between the two types of threshold, loss for speech is usually a better indication of the handicapping effect of hearing deficiency than the audiogram . . . this does not mean that the pure tone audiogram is unimportant. In interpreting hearing losses in fitting hearing aids, it reveals the pattern of loss and indi­ cates the type of frequency response which would be ?favorable*. ho i Davis^c Introduced the concept of the Social Adequacy

Hallowell Davis, "The Articulation Area and the Social Adeauacy Index for Hearing," Laryng.. 58 (1948), pp. 761-778.

Index of Hearing. This index was an attempt to combine both threshold and supra-threshold measurements using only the speech stimulus. The listening curve was similar to an ogive. To locate the base, Davis recommends the use of any of four threshold tests: Harvard #9 spondees, Harvard #12 sentences, Threshold of Intelligibility for Connected 22 Discourse, the Western Electric 4-C digits. Only two points are needed to locate the patient*s articulation curve— the hearing loss for speech obtained with the threshold tests and the level of his plateau. . . . We have at present, no substitute for the PB lists for measuring discrimination loss at high intensity, that is, the downard shift of the plateau. . . . The exact intensity at which the PB maximum score is measured is not critical. It is only necessary that it be at least 35 db above the patient^s threshold for test #9. The S.A.I. is an average of the percent of words heard correctly at the three standard levels of speech (soft, average, loud). It is based on two different types of speech tests; no inferences from pure tone tests are required. Discrimination loss— the inability to recognize difficult words even when spoken loudly— may depend upon high-tone hearing and/or psycholog­ ical factors.

43 ibid.

A tabular matrix has been worked out on which the hearing loss in db is located on the abscissa; the loss in percent articulation score is on the ordinate. The point of intersection gives the index of social adequacy. Walsh and Silverman^ and Eldert and Davls^5 compared

^ IT. Walsh and R. Silverman, "Diagnosis and Evalua­ tion of Fenestration," Laryng.. 56 (1946), pp. 536-555. ^5 e. Eldert and H. Davis, "The Articulation Function of Patients with Conductive Deafness," Larvng., 6l (1951)# pp. 891-909. 23 the shapes of articulation curves for patients with differ­ ent types of hearing loss* Both teams used successively higher levels of administration of the PB lists. Conductive loss groups show better mean scores with increasing sound pressure levels. Patients with pure nerve loss do less well than those with conductive impairments from about 25 db above speech reception threshold. The more severe nerve involvements reach a plateau soon after this

level. Results indicate that subjects with pure conductive

losses should achieve scores of around 90 percent; J 8 per­ cent (a very poor score) suggests nerve involvement. Eighty to eighty-eight is inconclusive since patients from all three groups scored in this range. The standard devia­ tion for scores obtained on the steeper part of the curve is approximately double that obtained near the plateau. A mean score for two lists is more reliable than the score for either one alone; however, monotony of the lists makes attention difficult to maintain for more than one. Some PB words are at best only slightly familiar, some not at all. List 8 is the hardest; 11 and 12 are easier. The rest are equally difficult. -The authors further note that the Social Adequacy Index table is valid only for tests given with their'recordings (the CID, Rush Hughes version.

46 Ibid. 24 Watson**'? notes that , "the poorer the ability of an

L. A. Watson, Manual for Advanced Audiometry, Minneapolis, the Maico Company, 1949, p. 30. individual to discriminate speech sounds, the greater is his relative difficulty in understanding the recorded PB test as compared with live voice testing." This is due to more limited range and greater distortion of the recorded test, so that a 90 percent score by live voice corresponds to 81 percent score on the recorded version. Shambaugh and Carhart**-® used speech audiometry in a

48 G. shambaugh and R. Carhart, "Contributions of Audiology to Fenestration Surgery," Arch. Otolaryn.. 54 (1951), PP. 699-712. diagnostic survey of potential fenestration cases. A cor­ relation for better ear average of 512-2048 with SRT was highly consistent in patients with otosclerosis. A discrep­ ancy between pure tone loss and SRT suggested possible psychogenic overlay. The PB lists were given as a discrirhlna- tion test at 25 db above SRT. Normal listeners and patients with pure conductive loss got high discrimination scores even at that level. Poor scores seem to indicate a loss other than purely conductive. 25 Francis Weille^ stated, "The great practical value

^9 Francis Weille, "Speech Audiometry in Practical Use," Arch. Otolaryng., 55.(1952), pp. 456-464. of speech audiometry is its usefulness in checking the valid­ ity of both air and bone conduction in pure tone audiograms in diagnosis." The 50 percent point of the SRT correlates with the air conduction audiogram while the PB or maximum discrimination test checks the validity of the bone conduc­ tion audiogram. This latter he always administers at 100 db or 67 db above the average speech reception threshold. He also administered the PB's at 100 db to normal listeners twice, at three month intervals. The first mean score of the group was 82 percent, three months later, 91 percent. "Scores of 40 to 50 indicate serious end organ damage, while a score of 80 percent or better means that a poor bone conduction curve can be disregarded." Some clinicians have developed word lists which were divided into high and low frequency stimuli, Intended to reveal the pattern of loss by the particular words missed. Utley^0 constructed tests specifically for vowel and

Jean Utley, "Relation Between Speech Sound Dis­ crimination and Per Cent of Hearing Loss, JSHD. 9 (1944), pp. 103-113. 26 consonant discrimination in hard-of-hearing children. Scores in each were correlated with pure tone thresholds and with percent loss computed by five different methods. Correla­ tions with hearing measures were significant while relation­ ships with age and intelligence were not marked. 51 52 Ersner and Saltzman, and Plummer, devised similar

5%iErsner and M. Saltzman, "Speech Hearing in Oto­ sclerosis," Arch. Q.V.. 46 (December, 1947), p. 753. 52 R. N. Plummer, "High Frequency Deafness and the Discrimination of High-Frequency Consonants," JSHD. 8 (1943), PP. 373-381. tests for discrimination of specific sounds, while Macfarlan53 has evolved tests which minimize education and

53 d . Macfarlan, "Speech Hearing Tests," Laryng., 55 (1945), PP. 71-115. . intelligence. The last author notes better performance in "more intelligent" patients which compensates for poorer auditory acuity. Beasley and Rosenwasser^ evolved a test which they

54 Willis C. Beasley and H. Rosenwasser, "Determin­ ing Factors in Composing and ASalyzing Speech Hearing Tests." Laryng.. 60 (1950), pp. 658-679. tried on five hundred patients with hearing impairments ranging from slight to severe. They analyzed their data by 27 group trerid methods to compare with the group audiograms. The most significant relationships were with the average loss in db at 1000, 1500 and 2000 cps. Approximately 28 percent of the cases did not conform, which implies that prediction of speech hearing ability from the audiogram is not valid for the individual case.

F. RESEARCH ON FACTORS AFFECTING HEARING FOR SPEECH

As the types and conditions of tests became standard­ ized, more research and thought was given to psychological and neurological aspects of hearing. Some factors, such as masking and context, had immediate bearing on wartime com­ munications. Others, such as binaural summation, had clin­ ical implications for testing procedures or fitting of aids. Articulation tests have proved useful for comparing communication equipment, for evaluat­ ing the effects of noise on communication, for determining the basic audibility of different words, and for rating and training communication personnel. The experimental variables involve the announcers, the test material, the communi­ cation link, and the listener (ability to hear sound, to discriminate speech sounds, and to resist masking noises). Such a list indicates the extensive matrix of variables that affect the results of an articulation test.55

55 j, L. Licklider and G. A. Miller, "The Perception of Speech," Handbook of Experimental Psychology (s. S. Stevens, editor), New York: John Wiley and Sons, Inc., 1951, P. 1043. £8 Differences between monaural and binaural thresholds.

Keys,-^ Pollack, ^ and Shaw, Newmanc! and Hirs^h^® demon-

^ John Keys, "Binaural vs. Monaural Hearing," JASA. 19 (1947), PP. 629-631. 57 1 . Pollack, "Monaural and binaural sensitivity for tones and white noise," JASA. 20 (January, 1948), p. 52. 58 W. Shaw, E. Newman, and I. J. Hirsh, "The differ­ ence between monaural and binaural thresholds.11 ,J. Exp. Psvch.. 37 (1947), PP. 229-242. strated that when stimuli are equated for difference in threshold, summation occurs. Summation may occur for white noise, speech, or pure tones, but is less marked for speech than for pure tones. Binaural and monaural pure tone thres­ holds. do not differ systematically as a function of frequency. With increasing difference between the two ears beyond 6 db, the binaural threshold approaches more and more closely that of the better ear. Most norms for speech hearing tests were obtained from monaural thresholds. Binaural measurements, then, may be expected to average about 3 db lower.: Frequency and intelligibility. Licklider and Miller^^

, 5 9 j.c.R. Licklider and G. A. Miller, "The Perception of Speech, Chapter 26. Handbook of Experimental Psychology (S.S. Stevens, editor), New York: John Wiley and Sons, 1951). review aspects of speech perception. "Intelligibility," 29 they note, "is impaired only slightly by the elimination of the very high and very low frequency components of speech."6°

60 Ibid.. p. 1064.

Radio and telephone take advantage of these findings and transmit only those components from around 250 to 3500 cps although the speech spectrum extends from below 100 to above 7000 cps. "The data (of Bell Laboratories) have been analyzed to show the effect on each of the individual speech sounds. . . . Eliminating the high frequencies affects consonant articulation scores more than vowel articulation scores,"

61 Ibid.. p. 1052.

and the reverse is also true. For long samples of speech, most of the energy occurs in frequencies below 1000 cps. For brief spurts, however, "the distribution of energy may be quite different, and it is these changes . . . that carry the perceptual clues."^2

~ ~ ' ' 1 ..... 62 Ibid.. p. 1041.

Miller^3 summarizes, ”... where discrimination is most

3 g . a . Miller. Language and Communication, New York: McGraw.Hill Book Company, Inc., 1951> p. 68. 30 acute, there is (l) the greatest capacity for handling infor­ mation and (2) the greatest contribution to the articulation scores for human speech." Intensity and intelligibility. Licklider and Miller^

^ J.C.R. Licklider and G. A. Miller, op. cit.. P. 1047;

cite several examples of the interdependence of intensity and type of material. For spondees,'average thresholds have been obtained within a range of 17 to 22 db. Most investigators have found average thresholds for monosyll­ ables at 30 to 33 db.

G. INDIVIDUAL DIFFERENCES IN AUDITION

Man investigators have pointed out that individual differences prevent accurate prediction of listening per­ formance. The area of research which has emphasized the preva­ lence of difference is that of supra-threshold listening. Pollack, Pickett, and Sumby65 tested conditions of

1 . Pollack, J. M. Pickett and W. H. Sumby, "Voice Identification of Speakers," JASA. 25 (1952), p. 823..

voice identification of from 2 to 16 speakers with varying length of speech samples. They reported very large Individual 31 differences in this ability among listeners, and suggested that in addition to the speech sample duration there is a large range in the ability of the listeners to encode com­ plex stimulus patterns for quick identification. Karlin studied several groups of speakers and

66 John E. Karlin, "The Problem of Selecting and Training Communication Personnel." Psycho-Acoustic Labora­ tory, Harvard University OSRD #987# 19^2. listeners under simulated battle noise conditions. Although he was testing a variety of interphonesystems, he found that good and poor speakers and listeners were differentiated regardless of the system used. The performance of all crews improved with practice, but the rank order of the listeners was largely unchanged. The groups used were both homogeneous and heterogen­ eous in regard to background, education, experience with interphones, and place of origin. In general, the laboratory (homogeneous) crews performed better. The performance of the groups varied with the equipment, but the amount of improvement was limited by the inherent efficiency of the listeners.

Two significant conclusions were drawn from the results: 1) differences between listeners were not apparent in quiet testing conditions— true listening ability of indi­ viduals was revealed only in noise; 2) there was little 32 relationship between pure tone thresholds and listening per­ formance. Although all members of the laboratory listening crew had normal acuity, they differed widely in listening ability. Karlin and others^ next developed a series of tests

67 j. E. Karlin, M. H. Abrams, P. H. Sanford, and J. F. Curtis, "Auditory Tests of the Ability to Hear Speech in Noise." OSRD Report 3516, Psycho-Acoustic Laboratory, Harvard University. to differentiate listeners for jobs in military communica­ tions. The same ability appeared to be measured by write­ down and multiple-choice forms of the three types of tests. There was little or no correlation between scores on the listening tests and scores on either intelligence tests (General Classification Test) or code aptitude and achieve­ ment tests. The research verified the earlier findings that individual differences are more apparent under the condi­ tions of listening in noise. Audiometric tests were not helpful in selecting good listeners. The authors conclude that the ability to listen in noise is a trait which cannot be predicted from other tests, but only from pertinent listening tasks. go Karlin previously had attempted to isolate either

^ John E. Karlin, "A Factorial Study of Auditory Function." Psychometrika. 7 (1942), pp. 251-279. a general auditory factor or specific subfactors which con­ tributed to auditory performance. He concluded that: "Except for cases of extreme deterioration of auditory appar atus, discrepancies were frequent between pure tone audio­ metry and successful prediction of hearing of the spoken voice and other complex acoustic stimuli. Auditory acuity might be the same in two people but auditory ability differs He factor analyzed 33 measures on 200 normal-hearing subjects between the ages of 15 and 19. One unidentifiable factor and eight identifiable factors were isolated. Five were of particular interest. 1. The loudness factor: neither time nor complexity but a pitch-loudness function, the strength of the psycho­ logical response to a given frequency. This was the only factor where intelligence loading appears, which indicates that this occurs at a perceptual rather than end-organ, sensory level. 2. The Auditory Integral or Perceptual Mass factor. This relates to mass and quantity; greater loudness and less time are perceived as the same mass as less loudness over more time. Too short stimuli, do not give the ear time to use the integrating function. Integration starts between .12 and .50 seconds after the initiation of the stimulus and lasts less than 1 second. It is not a part of the loud­ ness factor but over and above it.

3. Auditory Resistance (to distortion) factor. The 34 same ability seems to be operative in both synthesis and analysis. 4. Speed of Closure factor: the speed at which the stimulus must be recognized in order to be perceived. This ability affects both vision and hearing. 5. Incidental Closure factor. This appears to be a closure effect, transcending sense modality, dependent upon partial clues from the source of stimulation. No support appeared for either a first- or second- order general auditory factor. Rather, the study indicated that auditory function occurs on different levels and that any single factor will be a poor approximation to the com­ plete picture of hearing. In the age range tapped, growth had no effect. I.Q. was less marked in complex functions than might have been expected. CHAPTER III

PROCEDURE

This chapter will discuss the selection of subjects, measures used, facilities and equipment, and the scoring of tests.

A. SELECTION OP SUBJECTS

The subjects were fifty-one males, between the ages of 18 and 26, and forty-nine females between the ages of 18 and 22. All we® students in introductory psychology classes at The Ohio State University. They were selected on the bases of centile rank on the Ohio State Psychological Examination.1 Ten subjects were chosen from each decile.

1 Herbert A. Toops, Report to the Ohio College Association, 195^.

They were divided according to sex, either five and five or six and four, per decile. The sample was so selected in order to ensure that distribution of OSPE scores in the sample would be approxi­ mately the same as that in the population from which the sample was drawn. The OSPE is a group test, used as an aid in counsel­ ing and as a predictor of college grades. It consists of three verbal sub-tests: Analogies, Synonyms-Antonyms, and

35 Reading Comprehension. The student is given a centile rank for his Reading Comprehension score and for the total score. Subjects were assigned to deciles by their total ranks. All but six of the examinations had been administered within the last two years. Each subject was told that names had been selected randomly from groups of different ages, sexes, majors, and grade levels, and that the only requirement was normal hear­ ing. The experiment was explained as a comparison of per­ formance on listening to speech with that on two written language tasks. Subjects were well motivated since they received class credit for participating.

B. LANGUAGE MEASURES

The OSPE scores served as measures of language ability, which was the reason for their choice as a means of selecting subjects. An individual rather than a group test of vocabulary and intelligence employed was the Wechsler- 2 Bellevue scale. The vocabulary sub-test has a range of

2 David Wechsler, Measurement of Adult Intelligence. Baltimore, Williams and Wilkins Co., 19^4. easy-to-difficult words. It correlates highly with the other verbal sub-tests and with the total scale which in­ cludes performance tests. The vocabulary score alone 37 appears to measure both a specific language ability and gen­ eral intelligence. Credit was given everyone for the first four, easy words. The total raw scores were converted to "Verbal Intelligence Quotients," since these vary with age, particularly at the ages of these subjects. Another verbal measure was experimental. Shannon^

3 c. E. Shannon, "Prediction and Entropy of Printed English," Bell System Tech. J.. 30 (1951), P. 5^. had selected phrases and passages and asked subjects to guess them, letter by letter, with no cues for the first guess. He revealed the correct answer after each guessj errors were written below the line. The pattern of right and wrong guesses he called the "reduced text." Prom this he evolved three other experiments: l) let the subject continue guessing until he is correct, 2) select 15- letter phrases and have the subject guess these, 3) have him guess backward from letters already know. The scores on the last were only slightly poorer than the others. A fourth idea was suggested: guess from the reduced text. Mulder^ supplied 15-letter phrases, indicated-by a

^ Robert Mulder, "A Comparative Study of the Comper tence of Groups of International and Native Students in Aspects of Language that Hold Special Relevance to Speech." Ph.D. dissertation, The Ohio State University, 1953. series of dashes. He revealed the correct letter as soon as it was guessed or after ten unsuccessful attempts. For the present study, 18 five-syllable phrases were selected from the New York Times general news section. All began with the left edge of the columns but none began or ended sentences. The first sixteen letters (including spaces between words) were selected from each phrase and a diagonal line (/) was used to indicate the cut-off point. By the remainder system and a table of random numbers, 50 percent, i.e., 8 letters and/or spaces were removed from each phrase. This number was selected arbitrarily to give some structure for less apt subjects. Each phrase was printed on a separate card. (Appendix G.) In the exploratory study, each subject was adminis­ tered the first nine phrases and allowed one guess per letter. He guessed the letter aloud; the examiner replied "yes" or "no" and supplied the right letter if it had not been guessed. The subject recorded errors below the dash and filled in the correct response. Maximum score was 8 correct, 0 wrong; the reverse was the minimum. The second group of nine phrases allowed five incor­ rect guesses per letter. (Mulder had found ten too many.) All errors were written below the dash, correct answers were filled in. Maximum score was the same: 8 correct, 0 wrong. The poorest possible score was 0 correct, 40 wrong. "Correct" credit was given whenever the subject 39 guessed within the £ive-guess limit. The score, if all guesses were correct on the fifth trial, would be 8 correct, 32 wrong. In no instance did any phrase require for any subject as many as five trials for every letter. The subject was also timed in seconds for each phrase from his first glance at the card to the last correct guess. No allowance was made for the mechanics of speaking and writing. All three scores were given equal weight and the subjects were so informed (Appendix G, Instructions). Every preliminary subject reached his minimum per­ formance time for a single phrase by the fifth card, regard­ less of the difficulty of the phrase. On the basis of the results of the preliminary e^qperiment, the phrases were ranked on approximate difficulty according to mean time required and right and wrong scores per card. Five were selected from each group of nine: two easy, one intermediate, and two difficult. They were arranged for presentation in two groups, in order of difficulty within each group. Difficulty seemed to be associated 1) with deletion of spaces, which ran words together, 2) with deletion of the beginnings of words, and 3) with ambiguous, "information- full " possibilities where several words could fit and make equal sense. 40 C. EQUIPMENT

The hearing tests were administered in a sound- treated room with an ambient noise level of 30 db, as measured by a General Radio Sound Level Meter, Model 759, A Scale. A block diagram of! the room appears in Figure 1. The three speech tests were recorded and delivered diotical- ly— that is, with a single lead to a binaural headset. Equipment for the speech reception tests^ included a 5-watt,

5 c. V. Hudgins, J. E. Hawkins, J. E. Karlin and S.S. Stevens, "The Development of Recorded Auditory Tests for Measuring.Hearing Loss for Speech," Laryng.. 57 (1947), PP. 57-89. two Daven attenuators with a maximum output of 110 db, a pair of dynamic Permoflux PDR-3 earphones with flat frequency response below 4000 cps, to a maximum of 105 db, a Presto Transcription Turntable with a lightweight Pickering 190 professional tone arm, a Hewlett-Packard Voltmeter across the earphones to measure output and attenuation of the equip­ ment, a General Radio Sound Level Meter, Model 759, two 16-inch records and two 12-inch records of the three tests of speech reception (33 1/3 z’pm). For pure tone threshold determinations a Maico E-l discrete frequency audiometer was used. To time letter- guessing . a Standard time clock was employed which was cali­ brated in 10, 100, and 1000 seconds. CONTROL ROOM. SOUND-TREATED ROOM

PRESTO X PH0N06RAPH AMPLIFIER ATTENUATOR ✓ ATTENUATOR riwfv Ur 1 zft • y

V\ / Y/ Yy y / PDR-S Y EARPHONES MICROPHONE LOUDSPEAKER / / t t > = / 2

Figure 1 Block Diagram of Equipment Used to Deliver Speech Reception Tests 42 The records were calibrated by matching a 1000 cycle tone on the outside of the record to the rms deviation of the speech stimuli on the voltmeter. The amplifier attenu­ ator system was calibrated at the beginning of each session by adjusting the first attenuator so that the tone registered 0 db at 1 volt. Linearity was checked at the same time by attenuating the signal on the second attenuator and adjust­ ing the voltage until the signal to-noise ratio was 0 (-50 db).

D. HEARING MEASURES

Each prospective subject was tested for normal hearing acuity on four frequencies— 500, 1000, 2000, and 4000 cps— in five-db steps. Pure tone thresholds of subjects ranged from -10 to + 10 db. All speech reception tests were recorded. Two were cut from records issued by the Central Institute for the g Deaf, These were lists 50 and 50 of Harvard Auditory Test

g Central Institute for the Deaf, Research Department, St. Louis, Missouri.

Number 14 (spondaic dissyllabic words), and list Number 9 of the Harvard PB lists of monosyllabic words. (Appendices C and D.) The third test^ consisted of four lists of 19 words

^ E. Foladare, A Multiple-Choice Test of Word Recep­ tion. Unpublished Masters Thesis, The Ohio State University, 1952. each. The words were both dissyllabic and monosyllabic. Responses were given on a multiple choice response sheet with each correct response accompanied by 3 alternate, sim­ ilar-wounding choices (Appendix E). These were recorded on tape at The Ohio State University by a practiced speaker who attempted to produce all words with level inflection and equal loudness. The rms variation was + l'„5 db. Originally, the plan was to decrease the intervals between items on successive lists and measure response readiness by the trend of intelligibility scores from one list to another. However, the lack of any consistent trends in the scores, precluded using the results for this purpose. The measure which was used was simply the total intelligi­ bility score based on the number of words correctly recog­ nized for all four lists combined. The interval between words on List One was 2 seconds, 1.5 on List Two, 1.0 on List Three, and 0.75 seconds between words on List Four. The phrase, "Stand by for List Number ...., word Number One," introduced each list. There was no other carrier phrase. Four sides were cut of all the tests in order that no more than 25 playings per side would be necessary. Only the outer four inches of the 16-inch discs were used. E. PRESENTATION

All tests but the OSPE were administered individually The sound-treated room is rectangular and heavily padded. A double window at one end allows the experimenter to view the subject. One microphone is within the room and one at the control panel for directions and responses. The outer area is a relatively quiet, rectangular room. A double door sound trap opens on the basement corridor of the building. A block diagram of the room appears in Figure 2. For the Initial audiogram, the prospective subject was tested in the outer room. The left ear was tested first with ascending technique. The right ear was always second. Students with thresholds of plus 10 db or better were next given the speech reception tests in the sound-treated area. Spondees were administered first. The subject listened to the first 12 words, then was told to repeat what he heard. The signal was attenuated in 10- and 1-db steps to a level at which three out of six words were correctly repeated. The subject was then asked to repeat the 50 PB words. This recording was administered to all listeners at a level of 6l db. The score was in percent correct. The multiple choice test was administered last. The experimenter and subject read the instructions together. (Appendix E.) The sound pressure level was set at 4l dfe. | AUDIO- I I I Ulf™. L, J O -MICROPHONE G -TURNTASLE -LOUDSPEAKER ^ G j EARPHONES [4 VOLTMETER

ATTENUATOR -WINDOW ------t AMPLIFIER \' - -ATTENUATOR I

It'/* TRANSFORM!! PRE-AMP naCHAIRS

Figure 2 Block Diagram of Room Used in Experiment

-Fr Ul 46 Although the Wechsler-Bellevue test was designed to be administered orally, the answers were obtained in written form for this experiment (Appendix F). That the resulting scores would correlate highly with scores obtained from orally administering the test was determined by comparing the written responses with those in the manual. The sub­ ject sat in the outer room or in the corridor. Letter-guessing was performed in the outer room. Scores were recorded as each card was completed. The order of testing for each subject was hearing tests, letter- guessing, vocabulary, except when two or three subjects were scheduled for the same one and one-half-hour period. In this instance, an assistant administered the letter-guessing while the experimenter conducted hearing tests.

F. TABULATING OF DATA

All data for the subject were entered on his general information sheet (Appendix B). The following scores were recorded: OSPE, Two scores— total and reading comprehension centile ranks. Pure-tone audiogram, eight thresholds— four for each ear. (SRT) Speech reception thresholds, one score— the db level at which 50 percent of the spondees were repeated correctly. (PB) Articulation score, one score— the percent of correct responses given at 61 db. (MC) Multiple-choice test, one score— the total number of correct choices for the four lists. (W-B>) Vocabulary, three scores--raw score of total correct responses, weighted score, verbal I.Q. according to the subject's age. (L-G) Letter guessing, four scores per card, ten cards— performance time, number right guesses, number wrong guesses, total number of guesses for each phrase. The ten scores v/ere totaled at the foot of each column to give four total scores per person. CHAPTER IV

RESULTS AND DISCUSSION

One hundred subjects were administered a battery of three speech reception and three language tests. The sub­ jects were also tested to obtain eight pure tone threshold^. Relationships among 23 different scores were evaluated. Pearson product moment correlation and multiple R techniques were employed. The relationships evaluated were as follows: l) hearing with hearing (speech with speech, speech with pure tones), 2 ) language with language, 3 ) language with iwtf hearing fur speech and hearing for pure tones, 4) hearAfor speech with relative importance of selected language and pure tone measures. The Raw data are presented in Appendix A. Although three major variables were involved, the research is concerned primarily with the relationship be­ tween language ability and performance of tests of speech reception. Previous investigation-^ has shown significant

1 vide supra. Chapter 2.

relationships between hearing for speech and hearing for pure tones. The hearing for pure tones variable, thus, cannot be ignored, so it was held approximately constant by 48 restricting the subjects to those whose pure tone thresholds were within a narrow “normal" range.

A. HYPOTHESIS I

The null form of the hypothesis states that there is no significant relationship between threshold of hearing for the four frequencies tested and the following measures of hearing for speech: a. Speech reception threshold (SRT) in db, b. Speech discrimination score (PB) in per cent correct. c. Multiple choice (MC) score in total number correct. The thresholds were selected for statistical analysis on the following bases: a. The better (lower) threshold for each frequency in either ear (This corresponds to Carhart's "better ear,"), b. The threshold for each frequency in the "better" ear, c. Total (combined) threshold for each frequency, both ears, d. Total hearing loss, both ears, all four fre­ quencies. Hearing thresholds are relative to a zero line which is an average for the general population 20 to 24 years of 5° age. Normal limits include the better ear (-10 db) as well as slightly poorer (+10 db). To eliminate the signs, coded scores were assigned to threshold values: Coded Score Threshold in db 0 -10 1 - 5 2 0 3 + 5 4 +10 Figure illustrates the recording of the eigljt tres- holds on the individual general information sheet and the coding of the data into a form suitable for'analysis. Seven totals were derived from coded scores and could be converted into db if necessary. 500 1000 2000 4000 3 3 2 0 Left ear 5 5 0 -10 1 2 2 1 Right ear -5 0 0 - 5 2f 5 jj j- l 4

FIGURE 3. Illustration of Method of Recording and Coding Individual Audiograms

From this example, the following data would be used: (1) For analysis by frequency, better single threshold, either ear 500 1000 2000 4000 12 2 0 2) For analysis by frequency, better ear. The lower total 51 threshold of the right ear determines choice of ear. 500 1000 2000 4000 1 2 2 1 3) For analysis by combined threshold for each frequency, both ears 500 1000 2000 4000 4 5 4 1 4) For analysis by total hearing loss. The code does not weight one frequency over another. The American Medical Association computation of percent 2 loss assigns very low percent values at normal thresholds.

2 Howard A. Carter, "Estimation of Percentage Loss of Hearing," Jlfl.S.A.. 15 (1943), P. 8 7 .

Other studies, as reviewed in Chapter 2, have shown that the average of the better of the three thresholds from 500 to 2000 cps was most efficient for prediction to speech recep­ tion, This was also more significant than any single best threshold. Weighting, therefore, did not seem necessary for the normal thresholds of these subjects. Tables I through III summarize the coded thresholds for the four frequencies. These are arranged in OSPE deciles with total scores per decile. Figure 4 graphically shows the mean composite audio­ gram of combined thresholds for each decile. In general, there was some tendency for the lower deciles to have poorer 52 -TABLE I Summary of Hearing Loss in Coded Scores, Total for Each Decile. Better Single Threshold, Either Ear

Frequency Decile 500 1000 2000 4000

0 20 21 11 10 1 19 18 11 11 2 18 15 10 7 3 16 13 9 7 4 16 16 12 8 5 18 18 6 7 6 14 12 5 3 7 16 17 9 8 8 18 17 6 5 9 19 20 9 4

Sum

Mean Decile Total 17.4 16.7 8.8 7

* Code db 0 -10 1 - 5 2 0 3 5 4 10 53

TABLE II Summaryof Hearing Loss in Coded Scores, Total for Each Decile Better Ear Thresholds

Frequency Decile • 500 1000 2000 4000

0 20 21 14 15 1 21 23 11 16 2 19 16 13 9 3 17 14 9 8 4 17 18 12 10 5 21 18 8 10 6 14 14 7 8 7 18 17 10 12 8 19 14 7 3 9 20 20 9 9

Silimsr; of Scores 186 175 100 ^100 Mean Decile Total 18.6 17.5 10 10 54

TABLE III Summary of Hearing Loss in Coded Scores, Total for Each Decile. Total Thresholds, Both Ears

Frequency Decile 000 1000 2000 4000

0 47 47 33 31 1 46 45 34 34 2 43 42 31 24 3 37 31 24 16 4 41 43 35 23 5 43 41 21 22 6 35 31 24 17 7 45 42 27 25 8 41 42 22 17 9 45 44 25 21

Sums of Scores 423 418 276 229 Mean Decile Total 42.3 41.8 27.6 22.9 *Decile "Average" 21.7 20.9 13.8 11.5

*Note that "Average" of both ears is higher than Means -on either Table I or Table II. COOED SCORES Thresholds (both ears) foreach frequency in mean total codedscores foreach decile. Composite CombinedAudiogram for EachOSPE Decile. 500 SCORES DB ♦10 ♦15 1000 Figure4 CPS 2000

4000 6,8

55 hearing than the upper deciles. The third decile is a nota­ ble exception. Their better hearing is consistent with their performance in all other tasks in which they were superior to their adjacent deciles. To test Hypothesis I&. The speech reception thresholds were correlated with the various frequency threshold scores respectively. The correlation coefficients were:

Frequency Thresholds 500 1000 2000 4000

SRT/better ear .20* • .34** .27** .33** SRT/better single threshold .25** .05 .24* .15 SRT/total both . ears .19* .17 a .30** .12 SRT/total of all thresholds, both ears .34** **r significant at 1$ level -*r significant at 5$ level A3 4 ^relationships were low, although several were signifi­ cantly greater than zero at the one and five percent levels. For speech reception threshold, the most consistent, significant relationships are with the four frequencies in the better ear. When the better threshold for each fre­ quency was selected, the significant relationships appeared with 500 and 2000 cycles. Oftthe combined thresholds, only 2000 cps showed a significant relationships in the predicted 57 direction. The relationship between SRT and total hearing loss score was significant at the one percent level. Hypothesis la was rejected. There evidently is a relationship between SRT and tltal "hearing loss," better ear thresholds, and particularly thresholds at 2000 cycles. These correlations are consistent with, but lower than those in previous studies. To test Hypothesis lb the percent discrimination scores for PB monosyllables were correlated with thresholds for pure tones. High PB scores and low thresholds indicate better hearing. Negative correlation would therefore be predicted. The coefficients of correlation follows.

500 1000 2000 4000

PB/better ear .19* .13 -.23* .08 BB/better single threshold .03 .03 -.25** -.004 PB/total both ears -.02 -.07 -.30** -.07 PB/total of all thresholds both ears : -.173

**r significant at '1;% level. -#r significant at 5$ level

Consistent significant relationships as predicted ap­ pear only with 2000 cps. There is little or chance correla­ tion with most other frequencies. Hypothesis lb may be re­ jected only for the 2000 cycle threshold. For Hypothesis Ic. the total score of the multiple choice (MC) test was correlated with the pure tone thres­ holds. Again, high score on MC and low thresholds, "both represented better hearing, so a negative relationship was predicted. The resulting correlation coefficients were:

Thresholds 500 1000 2000 4000 MC/bet.ter ear .22* .38** -.01 e.03 MC/better single threshold .09 -.01 -.20* -.18 MC/total, both ears -.04 -.07 -.31** -.22* MC/total of all thresholds, both ears: -.28** **r significant at.1# level ~*r significant at 5#>level

The pattern of correlations, for this test and the better ear is similar to that for the PB list. The signifi­ cant relationships for 500 and 1000 cps are in the opposite direction from what would be predicted. This can be explained only by chance. Significant and predicted correlations occur with the 2000 cps threshold and total score, which is con­ sistent with those of the other two speech reception tests. Different from these, is a significant and predicted rela­ tionship with 4000 cps. With respect to these four correla­ tions then, Hypothesis Ic is rejected.

None of the pure tone and speech reception correlations 59 is as high as Harris® recommends (.70) nor high enough for

® J. D. Harris, "Free voice and cure tone audiometry for routine testing of auditory acuity," Arch. Otolarvng.. 44 (1946), pp. 452-467. individual prediction. However, the range is purposely nar­ row and the categories are limited. Tftese data were analyzed primarily to see if trends existed which were consistent with previous findings. In summary, all three speech reception tests correlate significantly better than zero with certain pure tone thres­ holds, particularly those for 2000 cps. The total audio­ metric pattern (which is comparable to "average" db loss of other investigators) also effect performance sufficiently to reject Hypothesis I. This series of correlations is summar­ ized in Table IV. B. HYPOTHESIS II

The second statistical hypothesis was concerned with the significance of the relationship among measures of hear­ ing for speech: SRT, PB and MC. Each speech reception test was correlated with each of the other two. The correlations with SRT would be predicted to be negative since high scores on PB or MC and low thresholds on SRT represent good perfor­ mance. The obtained correlation coefficients were: 60 SRT PB PB .27** MC .62** .07

**r significant at Vfc level.

Although the relationship between the two Harvard lists (PB abd SRT) is significantly greater than zero, the common variance is small. Both correlate with thresholds for 2000 cps, but are dissimilar in their relationship to the general audiometric pattern (combined total). These findings support the differences in their clinical use. The spondees are related to several pure tone threshold measure­ ments while PB?s are not. The question remains as to whether the PB^s measure "discrimination." The SRT, PB and MC tests are all tests of listening ability. The inter-correlations are, however, quite varia­ ble. An. explanation is not readily apparent, particularly for the complete lack of relationship between PB ahd MC. MC includes both monosyllabic and dissyllabic words. The gain in score per db of amplification is closer to that of SRT than PB, however. It may be this factor or the level of

administration, which was closer to threshold than to that for the PB*s, which makes, the relationship with SRT high while the other is so low. The 4l db level of administration was selected empirically as one where no subjects got 100 percent correct, 6l

TABLE IV Summary of Coefficients of Correlation Between Hearing for Speech and Pure Tone Thres­ holds

Threshold: SRT PB1 RR1

Better Ear 500 .20* .19* .22* 1000 .34** .13- .38** 2000 .27** -.23* -.0 1 -- 4000 .33** .0 8 - • -.03 Better Threshold — (either ear) 500 .25** .03 .09 1000 .05-- .03 -.01 2000 .24* -.25** -.20*. 4000 .15- -.004- -.1 8 - Total Thresholds 500 .19* -.02 -.04 1000 .17- -.07 -.07 2000 .30** -.30** -.31** 4000 .1 2 -- -.07-- -.22*- Total Hearing Loss .34** -.17 -.28**

**r significant at 1$ level ~*r significant at 5$ level

1 Note that high scores and low thresholds result in negative correlations. 62 but almost sill got better than 50 percent. The multiple choice form complicated the task. Restricting the number of choices to four should have made listening easier,^ but the

^ G. A. Miller, G- Heise and W. Lichten, "The Intell. of Speech as a Function of the Context of Test Materials," J. Exp. Pay.. 41 (1951), PP. 329-335. similarity of the alternatives evidently required greater discrimination. Previous research,5 however, showed that

5 Foladare, op. cit. scores did not differ significantly when the test was given in repeat rather than multiple choice form. Hypothesis II may be rejected for the relationships of speech reception threshold with the other two tests, but not for that of the multiple choice test with the PB*s. The re­ lationships are included in the summary of correlation coef­ ficients (Table V).

C. HYPOTHESIS III ■ In the null form, the hypothesis states that there are no significant relationships among the language measures: a. OSPE centile rank b. OSPE-RC (reading comprehension) centile rank c. Wechsler-Bellevue vocabulary (in verbal I.Q.) d. Letter Guessing (z) scores: 1) Total Z score for all three sub-scores TABLE V SUMMARY OP COEFFICIENTS OF CORRELATION BETWEEN HEARING FOR SPEECH AND LANGUAGE MEASURES

Language - Speech OSPE LETTER- guessing W-B Hearing. Total RC Total . Time Right Wrong Vocab SRT PB

OSPE-- RC .91** L.G. Total .31** -.27** Time .31** .35** .37** Right .17-- .0 6 -- .77** .02 Wrong ' .23* .16 .87** .05 .71** W-B Vocab. .72** .68** .25** .16 .09-- .19* SRT -.24-- -.19*- -.20*- . 05 -.25** -.27** -.18 PB .21* .28** -.05- .03 -.14-- -.03-- .24* MC .33** .27** .32** .09 .30** .29** .25** .07 **r significant at the 1$ Ifevel -*r significant at the 5$ level

Note: Low SRT with high scores in other variables produces negative correlation.

o\ oo 2) Time score 3) Right score 4) Wrong score Since the Ohio State Psychological Examination was already available, it served as a criterion for selection of subjects. It had two disadvantages, however: 1) it had been taken by the subjects at various times within the two years previous to the experiment, and 2 ) it was standard­ ized on a population of students entering The Ohio State University. The Wechsler-Bellevue vocabulary was individ­ ually administered, reflected the students present language development, and had been standardized on a non-college population. Each of the listening tests uses words which suppos­ edly are in the vocabulary of tenth grade, high school pupils. Difficult vocabulary, then, might not be related to these tests. Further, the tests Involve the probability of certain sound combinations occurring. Letter-guessing was developed as a predictor of probable letter sequencies in common words. Time was included partly as an intelligence indicator and partly as an element common to the listening tests. The validity of the whole measure was not known. The two scores of the OSPE were' used as separate measures, therefore their relationship to each other was tested. The coefficient was r =* .912 which is identical with that found by the testing staff for the OSPE on a recent sample of 2000 students. That the two did not corre­ late equally with all other measures suggests that the Reading Comprehension subscore is more specific than the total OSPE. The relationship of these two scores with the Wechsler-Bellevue verbal I.Q. was r = .72 for the OSPE and .68 for the Reading Comprehension. The difference between the two is not significant. The relation between the Wechsler-Bellevue and the OSPE total is demonstrated graphi­ cally in Figure 5. The four scores of the letter-guessing task were cor­ related with each other and with the three other language measures. The raw data were ^transformed to Z scores because l) time in hundreds of seconds was too large for easy compu­ tation, and 2 ) low time and error scores and high "right" scores represent good performance. The transformed Z scores were more easily compared. The sub-scores were then added, without being transformed again, to make a "total" score of the three Z*s. For example, Z scores of 45, 57, 72, for time, right, and wrong guesses, total 174. The parts of the test correlate with each other as follows: Time Right Wrong Right .02 Wrong .05 .71** Total .37** .77** .87**

**r significant at 1% level. WECHSLER-BELLEVUE (VOCABULARY) I.Q. 100 125 120 135 130 105 90 110 115 95 80 85 Computedfrom Wechsler-Bellevue Vocabularyfor Each the Means. h hc ie h .. TheHorizontal theLine Thick ConnectsLine, theS.D. Rangeand Standard Deviationof Intelligence Quotients SEDcl. TheThin LineRepresents OSPEthe Decile. Rangeand O 2 4 3 Figure5 SE DECILE OSPE 5 6 7 8 9

66

67 The relationships of right and wrong answers is high, of course, since by conditions of the test they are somewhat interdependent. The wrong answers, however, apparently influence the total score more than the other two measures, and may be the only one which it is necessary to record. Time was not related to the right and wrong scores. The correlation coefficients for each of the Z scores with each other language measure were: Letter-Guessing OSPE OSPE-RC W-B

Total .31** .27** .25** Time .31** • .35** .3.6" Right .06 .09 t Wrong .23* .16 .19* **r significant at 1$ ievel ~*r significant at 5# level

Although none of these coefficients is high enough for prediction of performance on other tests, total letter- guessing scores relate significantly to both OSPE ranks (see Figure 6 ) and to the Wechsler verbal I.Q. The highest rela­ tionship with the OSPE measures was with--time. Even though there is no time limit on the OSPE, students apparently pace themselves when they take it. Another interpretation might be Wechsler?s: "time is intelligence”; the brighter people can do more faster. However, one would then expecj? 6 David' Wechsler. Range of Human Capacities, Balti- more, The Williams and Wilkins Co., 1952, p. 110. TOTAL Z SCORES - LETTER GUESSING Eange andEange Standard Deviation of Letter-Guessing Total ZScores for Each OSPE Decile. 100 140 190 170 ISO 130 160 180 110 0 9 Figure6 SE DECILE OSPE

a higher correlation with the Wechsler for this factor. In­ stead, the significant relationship is with the error score. Both the Wechsler and OSPE are more highly related to the • number of wrong responses than to the number right. Thus the three general language measures are related — two are highly similar and the third overlaps yet measures different specific attributes. The hypothesis of no rela­ tionship among the language measures may be rejected. Re­ sults are summarized in Table V. page 6 3 .

D. HYPOTHESIS IV ft} * Hypothesis IV states in the null form that there is no significant relationship- among scores on the te'sts of language ability and on the tests of speech reception. In all but the speech reception threshold, high scores indicate better performance. For correlations with SRT, high scores with low thresholds result cin negative relationship. The coefficients of correlation appear below. SRT PB RR

OSPE -.24* .21* .33** OSPE-RC -.19* .28** .27** ) 1 00 H Wechsler . .24* .25** **r significant at 1$ level ~*r significant at 5$ level 70 The relationship between speech reception threshold and the two OSPE tests is significant at the 5 percent level. SRT and the Wechsler vocabulary are not significant­ ly related. The two other hearing tests, especially the multiple-choice, have a consistent significant relationship with the three verbal tests. Table VI shows group trends in terms of ten scores per decile. In order to show that there is an increase in the mean score on these tests from the lower to the higher deciles, the range and standard deviation is presented graphically in Figures 7 to 9. Such an increase is more marked for SRT and MC than for the PB articulation scores. It might be noted that, except for the third decile, the difference between the upper and lower half of the subjects appears as a marked jump rather than a gradual Improvement. Hypothesis IVd concerns the significance of the rela­ tionship between the four letter-guessing scores and each of the listening measures. Results appear in below. Low speech reception threshold and high Z scores yield negative correla­ tions. Total Time Right Wrong SRT: -.20* .05 -.25** .27** PB: -.05 .03 -.14~~ -'.03 ~ RR: .32** .09 .30** .20** ' ' • 1 **r significant at 1# level ‘ ~*r significant at 5# level SPEECH RECEPTION. THRESHOLD IN DB 20 26 30 29 28 23 22 34 33 25 24 32 27 .Thresholdsfor Each OSPE Decile. Rangeand Standard Deviation ofSpeech Reception v Eigure7 SE DECILE OSPE

71 PB ARTICULATION SCORE IN PERCENT 92 70 58 66 84 88 90 94 96 68 76 86 62 64 72 78 80 56 74 82 54 '-Rangeand Standard Deviation ofPB Articulation Scoresfor Each OSPE Decile. Figure8 OSPE DECILE OSPE

72 MULTIPLE CHOICE SCORES'- NUMBER CORRECT 32 30 36 42 48 0 4 44 46 50 38 52 54 56 98 0 6 66 62 68 70 64 74 76 1 . 0 Rangeand StandardDeviation of Multiple- ChoiceTest Scoresfor OSPE Each Decile

2

3

OSPE DECILE OSPE , Figure9 4

5

6

7

8

73 9 -TABLE VI SUMMARY OP TOTAL SCORES ARRANGED BY OSPE DECILE

-Language Hearing Decile OSPE OSPE-RC LG-Total W-B Total -SRT ,PB MC - Searing Loss

0 54 106 1425 972 157 245 784 484 1 146 173 1375 1036 159 238 800 484 2 239 320 1413 1046 140 245 838 504 3 352 423 1517 1110 108 218 808 517 4 441 477 1424 1101 147 243 820 503 5 557 593 1535 1145 127 245 854 530 6 653 654 1533 1116 107 220 786 559 7 745 681 1483 1174 145 214 828 548 8 829 802 1664 1204 122 211 830 558 9 957 922 1552 1224 134 218 846 537

Sums of Scores 4973 5151 14925 11128 1346 2297 8194 5224 Mean for N of 100 49.7 51.5 149.3 111.3 13.5 23 82 52 S.D. 28.8 27.6 21.2 40.1 5 4.1 5.8 4.5 75 The similarity between speech reception threshold and the multiple-choice test again appears. Both correlate significantly with the total, the right and the wrong scores. The PB scores generally have little relationship with those from the letter-guessing task. In summary, the PB discrimination test correlates more significantly with the difficult vocabulary measures.o The multiple choice test is significantly related to all the language measures but the time score. Speech reception threshold has a low relationship with the Wechsler and the time score and a significant correlation with all other language measure. The major hypothesis of no relationship between language and listening measures may be rejected generally with the cited specific reservations.

E. MULTIPLE CORRELATIONS

The multiple correlation technique was employed In an attempt to evaluate the relative importance of certain selected factors with respect to the variability of the ob­ tained scores of speech receptiai as measured by (l) speech reception threshold in db, (2) phonetically balanced list score, and (3) multiple choice test score. Each of the three speech reception measures was correlated as the dependent variable with the same seven independent variables, as fol­ lows: Ohio State Psychological Examination rank, Wechsler- Bellevue verbal IQ, Letter-Guessing total, total respective thresholds for both ears at the frequencies 500, 1000, 2000, and 4000 cycles per second. A summary of the data analyzed, the matrix and the inverse matrix required for the solution of the equations, and the resulting equations are presented in Appendix I. Each of the three obtained coefficients of multiple correlation is significantly different from zero. The values for speech reception threshold and for multiple choice test score as the dependent variables, .43 and .5 1 # respectively, are significant at the one percent level. The value for phonetically balanced list score as the dependent variable, .40, is significant at the five percent level. The pool of independent variables acting jointly could thus account for 18 percent, 25 percent, and 16 percent of the variation in speech reception threshold, multiple choice test score, and phonetically balanced list score, respectively. The estimated beta coefficients and their respective standard deviations are reported in Table VII. Only five of the 21 coefficients are significant: the letter-gues&ng task score and the threshold at 2000 cps both contribute significantly to the speech reception threshold and to the multiple choice test scores; the threshold at 2000 cps contributes significantly to the phonetically balanced list score. In view of the low coefficients of multiple correla­ tion and the relatively few beta coefficients significant 77 TABLE VI! ESTIMATED COEFFICIENTS AND CORRESPONDING STANDARD DEVIATIONS AND RATIOS FOR COMPUTING . . MULTIPLE X'S -

OSPE W-B . L-G 500 1000 2000 IfOOO

Estimated Coefficients

SRT -.0132 -.0091 -.0^-55* .H037 .18^3 .6988* -.1705 PB .0109 .1208 -.0272 .3729 .1802 -1.1936** .2927 MC .0313 .0333 .-104-2** .10W .1^23 -1.366*+**- .1780-

Standard Deviations of Estimated Coefficients

SRT .0202 .0558 .0200 . 302h -309b .28^3 .2190

PB .0291 .080^- .0287 A 3 55, .^56 .k096 .315^ MC .03^1 .09^ .0337 .5096 .52A A792 '.3690

Ratios of Estimated Coefficients/Standard Deviations

SRT -0.655 -0.162 -2.280* 1.335 -0.596 2 A 57* -0..779 p b ’ 0.37^ 1.503. -0.9A 0.856 O.lKA -2.91^* 0.928

MC 0.920 0.35^ 3.09^* 0.206 0.273 -2.851** -0A82

** significant at 1% level * significant at 5% level for generalization to the population from which the sample was drawn, the equations are of little practical use for the purpose of predicting any of the three speech reception measures. Some inferences, however, with respect to the theoretical question of the factors influencing speech reception and their relative strengths may he drawn from comparisons among the ratios obtained by dividing each esti­ mated coefficient by its standard deviation. These ratioq are reported in Table VII. The rank order of the seven ratios obtained for any one of the speech reception measures indicates the rank order of the contribu­ tions of the corresponding seven independent variables to the corresponding multiple correlation coefficient. The extent to which the ratios correspond with respect to rank order of absolute value from one set to another for the three speech reception measures is not marked. The ranks of one and two in each of the three sets of ratios, however, belong to the threshold at 2000 cps or to one of the three language measures. The assumption that hearing acuity at 2000 cps and language ability are relatively important in the pool of seven independent variables appears reasonable. If true, a deficiency in one of the two above-mentioned factors might be compensated for by a proficiency in the other. For the remaining rank order, no definite pattern appears which can be readily interpreted.

Only a small percent of the variability of any one of 79 the three speech reception measures is to be explained by the combined influence of 'the pool of seven independent variables employed in calculating the multiple correlation coefficients. The remaining and larger percent is due to something else. Speech reception is evidently strongly influenced by factors other than those evaluated here.

F. DISCUSSION

Three measures of hearing for speech were compared with three measures of language ability in a college group of normal-hearing subjects. Some of the obtained Pearson r?s were not significantly different from zero. Most of those which are significant were quite small. The low relationships may be due, in part, to the homogeneity of the sample. Although subjects were hetero­ geneous with respect to OSPE scores, they were fairly homo­ geneous in some other respects. The restricted range of pure tone thresholds would lead to low correlation coefficients with this variable. Subjects with hearing loss might have shown relationships more conclusively. Any demonstrable correlation between pure tone hearing and hearing for speech was not necessarily to be expected, since all speech reception measures, too, might have been expected to fall within the normal range. There were, however, occurrences of elevated speech reception thresholds and of poor discrimination per­ formances. 80 All subjects had been in college at least two quar­ ters. A previous study? had shown differences in listening

7 E. Foladare. Unpublished data, The Ohio State University, 1953 performance between entering freshmen and all other levels of college students, but not among the latter. Among the sub­ jects of the present study, only the two lowest OSPE deciles were strikingly poorer in listening performance than the other eight. The two top groups were somewhat superior. According to the Wechsler vocabulary test results, the mean IQ for the group was 111, as compared to an expected mean of 100 for the general population. The distribution as a whole was farther up the IQ scale than that of the stand­ ardizing group. The three lowest deciles are still within the "normal" range of 900 to 110, while the two highest are just past 120 or "superior," (see Figure 4). Three subjects had "very superior" IQls of 130 or better and two fell below 90. The subjects also had, on the average, better hearing acuity at 2000 cps. As a group, however, their listening performances were not better thaa average. Karlin^ has suggested that true differences in listen-

8 J. E.Karlin, "Auditory Tests of the Ability to Hear Speech in Noise." 0SRD.3516. Washington D.C. Dept, of Commer. 1944. ing ability are revealed in noise rather than quiet. The 81 present study was intended to duplicate quiet clinical test­ ing conditions. It might have been advisable to include at least one listening task in noise to widen the narrow range of individual differences. The scores on the letter-guessing task which was an experimental language test, may have been biased by certain personality aspects. This had not appeared to the same de­ gree when the preliminary tests were made on a smaller group of graduate students. Most students in the OSPE deciles short of the extremes did not seem disturbed by being timed, but concentrated on right and wrong choices. The very bright and the low normal, however— in spite of the” instructions— seemed unduly fearful of making wrong responses, even though they knew they were losing time. They became generally more disturbed and tense as the task progressed, and frequently made remarks about how "poorly" they were doing. This might have occurred regardless of timing. Also, the upper decile subjects with larger vocabularies often sawwseveral alterna­ tives which would fit into the spaces; they made accurate deductions after trying two or three logical choices. Some of the above-discussed tendencies appeared in the listening performances. Subjects in the ninth OSPE decile and some from the eighth— subjects who were by far more intelligent and alert than the majority of the group— were consistently fearful of making wrong responses even in the two types of threshold determinations. Most of the other 82 subjects did not hesitate to repeat what they thought they heard, and they expected to make some mistakes. The super­ ior subjects often asked for immediate scoring of tests and for their relative ranks with the others. How this anxiety affected their true scores is not known, since these are qualitative aspects of performance. Anxiety— or something— apparently did depress the performance of the highest and lowest groups, as may be seen in Egures 4-9. It is worth noting, too, the lack of a steady progression toward better performance from low to high deciles. Rather, there is a relatively horizontal line connecting the means of the lower half of the subjects (excepting the decile #3), and a an­ other connecting the means of the upper half. A sharp cut­ off occurs at either the fifth or sixth decile. The excep­ tions to this pattern are for the PB scores and for the Wechsler vocabulary I.Q.?s. These exceptions cannot readily be explained. The relation of these distributions to perform­ ance on hearing at threshold levels suggests that addition is affected by a combination of intellectual, sensoiy, and per­ sonality factors.

G. RECOMMENDATIONS

1. The relative importance of the contributions of the various factors to listening ability might be determined more precisely if articulation tests were administered in varying levels of white noise. 2. The letter-guessing task might be further explored and refined if it were given untimed to representative intel­ lectual groups. The observed reactions might prove to be un­ related to timing and to be a part of the penalty of being wrong. 3* The responses to the letter-guessing task might afford a probability measure of diagram and tri-gram combin­ ations in English as well as a possible measure of intelli­ gence. v CHAPTER V

SUMMARY AND CONCLUSIONS

A. SUMMARY

One hundred normal-hearing college students were selected according to their ranks on the Ohio State Psycho­ logical Examination. There were ten subjects from each decile, equally divided as to sex. They were determined audiometrically to have pure tone thresholds of 10 db or better at 500, 1000, 2000, and 4000 cps. Individually all were administered three recorded tests of speech reception— spondees to obtain the speech reception threshold, PB?s at 61 db (re ,0002 dyne/cm2) for an articulation score, and a multiple-choice test at 41 db as an additional discrimination measure. The OSPE rank and the OSPE reading comprehension sub-score were used as measures of language ability. Each subject also wrote definitions for .the Wechsler-Bellevue vocabulary test; the score was converted into a verbal intel­ ligence quotient. A third language measure was experimental; the test consisted of guessing the missing letters in 16- letter phrases from which 8 letters had been removed at random.

Pearson product-moment correlations were used to test the relationships among scores on the three speech reception 84 85 tests, pure tone thresholds, and the language measures. The multiple correlation technique was employed to evaluate the relationship between (1) speech reception threshold in db as the dependent variable and the three major language measures and the four total tone thresholds as the independent variables, (2) the PB score as the depend­ ent variable and the same seven Independent variables, and (3) the multiple choice score as the dependent variable and the same seven independent variables.

B. CONCLUSIONS

In spite of the restricted range of pure tone thresh­ olds, significant correlations were obtained between these and the listening tests. It may be.concluded that speech reception threshold is related to hearing for pure tones in the better ear, to hearing in either ear at 2000 cps, and to the total audiometric pattern. PB scores, however, are significantly related only to thresholds at 2000 cps. The multiple choice test results correlate most highly with the total thresholds for 2000 and 4000 cps and with the whole audiometric pattern. If these relationships are apparent even for normal-hearing subjects, they should be more marked where hearing loss is present. The pattern of relationships among the speech reception tests cannot readily be explained. The speech reception threshold has a low significant correlation with the PB test 86 and a much higher one with the multiple-choice test. The PB and MC tests, however, seem to be totally unrelated.; performance on one cannot be predicted from performance on the other. According to evidence obtained from multiple corre­ lations for normal-hearing subjects, hearing acuity at 2000 cps and language ability, as measured in this experiment, are relatively Important determiners of speech reception, as measured in this experiment. Other factors not investi­ gated are apparently even more important, as indicated by the large percent of variability in listening scores left unexplained. BIBLIOGRAPHY BIBLIOGRAPHY Beasley, Willis C., "Normal Hearing for Speech in Each Decade of Life." National Health Survey Hearing Studies, Bulletin "No. 5. Washington, D.O.: U. S. Public Health Service, 1938. ______, "Normal Hearing by Air and Bone Conduction; Dif­ ferences and Age Variations in Hearing Loss in Rela­ tion to Stage of Deafness." National Health Survey Hearing Studies. Bulletin No. 6. Washington, D.C.: USPHS, 1938. ______, "Correlation Between Hearing Loss Measurements by Air Conduction on Eight Tones." Journal of the Acoustical Society of America..12:104-113, 1940. ______, "Characteristics and Distribution of Impaired Hear­ ing in the Population of the United States." JASA, 12: 114-121, 1940. ' ______, and Harry Rosenwasser, "Determining Factors in Composing and Analyzing Speech-Hearing Tests." Laryngoscope. 6 0 :658-679, 1950. Carhart, Raymond B«, "Individual Differences in Hearing for Speech." Annals of Otology. Rhinology and Laryn­ gology. 55:223-67, 1946. ______, "Monitored Live Voice as a Test of Auditory Acuity." JASA. 17:339-49, 1946. ______, "Speech Reception in Relation to Pattern of Pure Tone Loss." Journal of Speech and Hearing Disorders. ll:97ttH08 , 23W. : ------:— ______, "Selection of Hearing Aids." Archives of Otolaryn­ gology., 44:1-18, ;947. Carter, Howard A., "Estimation of Percentage Loss of Hearing. JASA, 15:87, 1943. Cherry, E. Colin, "Some Experiments on the Recognition of Speech," JASA. 25:975, 1953. Curry, E. Thayer, "The Relation Between Hearing Loss for Specific Frequencies and the Distance at which Speech Can B^ Identified." Ann. Otol.. Rhin.. and Larvng. 33-9 , 1949. . ------—— 88

Davis, Hallowell, "The Articulation Area and the Social Adequacy Index for Hearing." Laryng, 5 8 :761-78, 1948. ______, The Psychophysiology of Hearing and Deafness." Chapter 28. S. S. Stevens, editor, The Handbook.of Experimental Psychology. New York: John Wiley and Sons, 1951. Dudley, Homer, "The Carrier Nature of Speech." Bell System Technical Journal. 19:495-515* 1940. Dunn, H. K. and S. D. White, "Statistical Measurements on Conversational Speech." JASA. 11:278-88, 1940. Egan, J.,^Articulation Testing Methods." Laryng.. 58:955-91*

______and Francis Weiner. "On the Intelligibility of Bands of Speech in Noise." JASA. 18:435-39, 1946. Eldert, E. and H. Davis, "The Articulation Function of Patients with Conductive Deafness." Laryng.. 6l: 891-909, 1951. Ersner, M. S. and M. Shltzman, "Speech Hearing in Otoscler­ osis." Arch. Otolaryng...46:753 ff, 1947. Falconer, G. A. and H. Davis, "intelligibility of Connected Discourse as a Test for the Threshold for Speech." Laryng.. 57:581-95, 1947. Fletfcher, Harvey, Speech and Hearing. New York: D. Van Nos­ trand Company, Inc., 1929. ______, Speech and Hearing in Communication. New York, D.Van Nostrand Company, Inc., 1953* 46l pp. ______, "Calculating Hearing Loss for Speech." JASA. 22:1-5. 1950. ______and J. C. Steinberg, "Articulation Testing Methods." Bell Svst. Tech. J.. 8 :806-54 (1929). Fowler, E. P., "Hearing Standards for Acceptance, Disability Rating, and Discharge in the Military Service and Industry.£ Laryng. 51:937-56, 1941. £_____ , "Is the Threshold Audiogram Sufficient for Determin­ ing Hearing Capacity?" JASA. 15:57-60, 1943. 8 9

•____ , "The Percentage of Capacity to Hear Speech and Re­ lated Disabilities," Laryng. (1947) 57:103-113* French, N. R. and J. C. Steinberg,"Factors Governing the In­ telligibility of Speech Sounds.j? JASA. 19:90-119, 1947* Harris, J. Donald, "Free Voice and Pure Tone Audiometry for Routine Testing of Auditory Acuity." Arch. Otolaryng. 44:452-467, 1946. ______, "Some Suggestions for Speech Reception Testing." New London, Conn.: Naval Med. Res. Lab. Report No. 2.. Project NM 003-021, 1948. ______, H. L. Haines, and C. K. Myers, "Loudness Perception for Pure Tones and for Speech." Arch. Otolaryng. 55: 107-33, 1952. (or USN Med. Res. Lab. Rep. No. 156, 1950) ______and C. K. Myers. Experiments on Fluctuation of Audi­ tory Acuity. New London, Conn.: USN Med. Res. Lab. Report No. 196, 1952. Herman, George, "Variability of the Absolute Auditory!-Thres­ hold." JASA. 25:822, 1953. Hirsh, Ira J. "Clinical Application of Two Harvard Auditory Tests."JAHB. 12:151-58, 1947. ______, "Binaural Summation— A Century of Investlgi tion." Psych. Bull. 45:193-206, 1948. ______, The Measurement of Hearing. New York: McGraw-Hill Book Company, Inc., 1952, 364 pp. Hudgins. C. V., J. E. Hawkins, J. E. Karlin, and S. S. Stevens, The Development of Recorded Auditory Tests for Measur­ ing Hearing Loss for Speech." Laryng. 57:57-89, 1947. Hughson, W. and Eva Thompson, '-"Correlation of Hearing Acuity for Speech with Discrete Frequency Audiograms." Arch. Otolaryng. 36:526-40, 1942. Karlin, J. E., "A Factorial Study of Auditory Function.}! Psychometrlka. 7:251-79, 1942. > The-Problem of Selecting and Training Communications Personnel. Psycho-Acoustic Laboratory, Harvard Uni­ versity, OSRD Report No. 987, 1942.

______, Auditory Tests of the Ability to Hear Speech in Noise. Psycho-Acoustic Laboratory, Harvard University, OSRD Rep. No. 3516, 1944. 90

______, Auditory Tests for the Ability to Discriminate the Pitch and Loudness of Noises. Psycho-Acoustic Lab. Harvard University, OSRD Rep. No. 5294, 1945. Kelley, Noble H. "A Comparative Study of the Response of Normal and.Pathological Ears to Speech Sounds.;” J. Exp. Psychol. 21:342-52, 1937. , "A Study in Presbycusis.” Arch. Otolaryng. 20:506- 13, 1939. Keys, John W., “Binaural vs. Monaural Hearing.” JASA. 19: 629-31, 1947. Licklider, J. C.R. and George A. Miller, "The Perception of Speech,” Chapter 26. B/S. Stevens,.editor, The Hand­ book of Experimental Psychology. New York: John Wiley and Sons, Inc., 1951. Lightfoot, C. R. Carhart, J. Jerger, Efficiency of Impaired Ears in Noise with Perception of Speech at Supra- Threshold Levels. Randolph Field, Tex., USAF School AV. Med. 1953 PB 113580. Myers, C. K. and J. D. Harris, The Inherent Stability of the Auditory Threshold. New London Conn: USN Med. Res. Lab. Report No. 3, 1949. Miller, George A., Language and Communication. New York: McGraw-Hill Book Company, Inc., 1951, 298 pp. ______, G. Heise, and W. Lichten, "The Intelligibility of Speech as a Function of the Context of the Test Mater­ ials." J. Exp. Psychol.41:329-33. 1951. ______and J. A. Selfridge, "Verbal Context and the Recall of Meaningful Material." Amer. J. Psychol.. 63:176- 85, 1950. Munson, W. A., "How Little We Hear." Bell Laboratories Record. 21:341, 1943. . : Mueller, Werner.- "The Clinical Examination of the Hard of Hearing." Ann. Otol.. Rhin.. and Laryng.. 51:756 ff. 1942.

McFarlan, Douglas, "Speech Hearing and Speech Interpretation Testing." Arch. Otolaryng.. 31:517-28, 1940.

______, "Speech Hearing Tests." Laryng.. 55:71-115, 1945. 91

______, "Testing Speech-hearing and the Efficiency of Hear­ ing Aids." Ahn. Otolaryng.. 57:444-52, 1948. Plummer, R. N., "High Frequency Deafness and Discrimination of High Frequency Consonants." JSHD.. 8:373“8l, 1943. Pollack, Irwin, "Monaural and Binaural Threshold Sensitivity for Tones!and for White Noise." JASA.. 20:52 ff. 1948. ______, "Effects of High Pass and Low Pass Filtering on the Intelligibility of Speech in Noise." JASA., 20:259-66. 1948. ______, J. M. Pickett, and W. H. Sumby, "Voice Identifica­ tion of Speakers." JASA.. 25:823 ff, 1953. Reymert, M. L. and M. Rotman, "Auditory Changes in Children from Ages 10 to 18." J..Genet. Psychol. 68:181-87 1946. Sabine, P. E., "On Estimating Percent of Loss of Useful Hear­ ing." Transactions of the American Academy of Oph­ thalmology and Otolaryngology. (March-April. 1942). Shambaugh, George and Raymond Carhart, "Contributions of Audiology to Fenstration Surgery." Arch. Otol. Rhin. and Larvng.. 54:699-712, 1951. Shannon, Claude E., "Prediction and Entropy of Printed English." Bell Svst. Tech. J.. XXX:50-.1951. ______and Warren Weaver., Mathematical Theory of Communica­ tions. Urbana: Univ. of Illinois Press, 1949. Shaw, W. A., E. B. Newman, and I. J. Hirsch, "The Difference Between Monaural and Binaural Thresholds." JASA/, 19: 734 ff, 1947. . “ Silverman, S. R., "Tolerance for Pure Tones and Speech in Normal and Defective Hearing." Ann. Otol., Rhin.. and Laryng., 5 6 :658-77, 1947. ______, "Use of Speech Tests for Evaluation of Clinical Pro­ cedures." Arch, of Otolarvng.. 51:786-97, 1950. ______, W.R. Thurlow, T.E. Wals, and H. Davis, "Improvement in the Social Adequacy of Hearing Following the Fenes­ tration. Operation." Larvng.. 5 8 :607-31, 1948. Smithy M.H. and J.C.R. Licklider, "Statistical Bias in Compar- • Isons of Monaural and Binaural Thresholds.?, Psychol. Bull., 278-248, 1949. . ; 92

Steinberg, J. C., H.C. Montgomery, and M.B. Gardner, "Results of the World^s Fab Hearing Tests." Bell Syst. Tech. J. 19:533-62, 1940. Stevens, S. S. and H. Davis, "Hearing, its Psychology and Physiology. New York: John Wiley and Sons, 1938, 489 pp. Thurlow, W.R., S.R. Silverman, H. Davis, and T.E. Walsh, "A Statistical Study of Auditory Tests in Relation to. the Fenestration Operation." Laryng.. 58:43-66, 1948. ______, H. Davis, T.E. Walsh, and E. Elder, "A Third Statis­ tical Study of Auditory Tests in Relation to the Fen­ estration Operation." Laryng.. 61:124-37, 1951. Toops, Herbert A., Twenty-Ninth Annual Report of the Commit­ tee on Technical Research. Bulletin 150, Columbus, Ohio College Assn., 1953-54, pp. 2720-2753. Trowbridge, Barnard C. "Correlations of Hearing Tests." Arch. Otolaryng..45:319-34. 1947. Utley, Jean, "The Relation Between Speech Sound Discrimination and Percent of Hearing Loss." JSHD.. 9:103-113, 1944. Watson, Leland A. and Thomas Tolan, Hearing Tests and Hearing Instruments. Baltimore, The Williams and Wilkins Com- pany, 1949, 597 PP. Wechsler, David, The Range of Human Capacities. Baltimore, The Williams and Wilkins Company, 1952, Second. Ed. ______, The Measurement of Adult Intelligence. Baltimore, The Williams and Wilkins Company,1944. Weille, Francis L., "Speech Audiometry in Practical Use." Arch. Otolaryng. 55:456-64, 1952. Westlake, Harold, "Reality of the Zero Reference Line for Pure Tone Testing.1' JSHD. 8:285 ff., 1943. Wever, Ernest G., "Recent Investigations of Sound Conduction." Part II. The Ear with Conductive Impairment." Ann. Otol.. Rhin.. and Larvng.. 59:1037-62, 1950.. Wishart, E. S., "Practical Methods of Testing Hearing for Hospital and Offices." Canadian Medical Assn. Journal. 55:567-71, 1946, . ' ~ 7 APPENDIX A. 9*+

TABLE VIII NUMBER OF MALE AND FEMALE SUBJECTS FOR EACH OSPE DECILE

OSPE Rank Male Female Total

0 - 9 5 5 10 10--19 5 5 10

20--29 6 b 10

30--39 5 5 10

IfO--if9 b 6 10

i \0 'S 5 5 10 • 1 • 60--69 6 if 10 1 0 -o -79 6 b 10 80--89 5 5 10 90--99 i+ 6 10

Total 51 *f9 100 APPENDIX B 96 GENERAL INFORMATION'SHEET NAME ______NUMBER AGE ______SEX______GRADE______(nearest birthday) MAJOR______;______;______DATE______PURE TONE THRESHOLDS: 500 1000 2000 1*0000 Left ear Right ear

SRT______db PB SCORE___ ft MULTIPLE CHOICE ______correct

VOCABULARY,______X 5 I-1-Q.1. Score Wt'd. score LETTER GUESSING No. Time Right Wrong Total 1 1. ____ 2. ______

3* ' ______

if. ______

5.______

6. ' ______

7 - ______8. _ _ ___ 9 . ______10. ______Total APPENDIX C HARVARD AUDITORY TEST 1** List 5c List 5d oatmeal grandson dugout highway coughdrop outside daylight lightbulb icebox toyshop hardware yardstick shotgun housework wildcat hotdog dug out iceberg doorway playmate earthquake mushroom oatmeal daybreak headlight beehive baseball workshop airplane scarecrow whitewash doormat playground jacknife birthday horseshoe eyebrow workshop doorstep grandson whitewash lightbulb coughdrop wayside hardware pancake stairway farewell mousetrap washboard bloodhound j acknife sidewalk farewell eyebrow toothbrush bloodhound doormat ship week outside birthday cookbook icebox sundown backbone greyhound schoolhouse scarecrow cowboy footstool playground platform churchbell doorway northwest woodchuck wildcat platform sunset toyshop northwest padlock shotgun blackout lookout eardrum armchair beehive blackboard highway airplane footstool. daylight daybreak churchbell lifeboat baseball wayside firefly housework stairway sundown floodlight pancake schoolhouse blackout mousetrap greyhound armchair schoolboy cowboy eardrum railroad hotdog blackboard starlight yardstick horseshoe rainbow iceberg doorstep toothbrush earthquake washboard shipwreck woodchuck sidewalk cookbook sunset lifeboat backbone padlock firefly starlight lookout schoolboy rainbow railroad playmate mushroom APPENDIX D 100 HARVARD PB MONOSYLLABIC WORDS. List 9

1. chess 26. tax 2. smart 27. carve ?• root 28. throne k. thank 29. nuts 5.. arch 30. birth 6., weak 31. noose 7. than 32. ten 8. with 33. troop 9- lit 3k. skill 10.. grace 35. odd 11. crowd 36.. reed 12. chest 37. spud key 1 ?' 38. wipe ■■ 1*4-. fume ditch 15. club & gate - 16. give *4-1. mass 17. phone *4-2. clown 18. bit *4-3. foe 19. rude k±. itch 20. nerve **•5. sip 21. flag if 6. hoof 22. toad *4-7. tub 23. ice if 8. fuse 2k. wild if9. year 25. beef 50. boost APPENDIX E MULTIPLE CHOICE TEST INSTRUCTIONS On the last two pages are four lists of words numbered from 1 to 19. Opposite each number is a group of four words which sound alike.. You will hear a speaker say only one

Example: (Speaker) "fetch" 1. bench theft -¥eteh- thatch

There is very little time between words so listen carefully.- There will be a longer pause between each list, but the time between words will be less on list 2 than on list 1, still less on 3S and least on *+. You are not expected to get every word; just do the best you can. To help you prepare for this, here is a practice list of 20 words. Each group of five will be presented: at the same increasing speeds as the longer lists. Ready? 103 PRACTICE LISTS

1. groove drew crew grew 2. modern moderate modesty modest 3. .vice fight mice bite 4. say stay stayed spade 5. forbade pervade surveyed survey

1. chink kink check chin 2. drunk grunt brunt runt 3. harrow peril herald arrow 4. drum rung rum run 5. putter tucker pocket pucker

1. need lead lean leave 2. spring pray spray spread 3. amiss omit amid emit 4. lamp lance glance land 5. airy hairy arid carry

1. stance stand stamp spent 2. science silent sound silence 3. code told cold coal 4. pillow pillar killer filler 5. barter barker sparkle parker Now turn tfce page for list 1. 104

LIST 1 LIST 2

1. bargain pardon fog foggy 1. begot forgot begun deduct 2. rocky rock rocket rotten 2. cattle tablet habit fable 3. lodge large live lie 3. carry fairy berry very 4. evil eagle either even 4. ivory island eyelid idle 5. trip tress press dress 5. mood moon move smooth 6. Lincoln lengthen link 6. meter meager leader ointment neither 7. ran rag rank rang 7. lawless Wallace laws loss 8. eager meager maker meter 8. cheer gear year jeer 9. swing slang flying slimy 9. shudder shutter shuffle shuttle 10. bower power flower borrow 10. dive died guide die 11. saw sought sauce soft 11. debate debase deface base 12. trouble crumble crumple couple 12. pike kite type tight 13. valley valor balance valid 13. truth true troop fruit 14. back stack spat fat 14. brim rim grin grim 15. hide high pie tie 15. shower scholar sour scour 16. clearly quarry query weary 16. wide wise why ride 17. dive guise guide dies 1 7. feet seat seek speak 18. bay vague may they 18. knack mask match Mack 19. gaze gain gave gay 19. group root droop roof

Score: Score: LIST 3 LIST 4

1. pack package packet 1. hold boy foliage holy Packard 2. dimple temple simple 2. blessed glisten blessing pimple lesson 3. deepen beaten beet beacon 3. lounge round long loud 4. because diploma depart 4. paper faithful faithless default fateless 5. warrant warm one warn 5. linden linen Lincoln Linda 6. rubbish radish reddish 6. pathless famous base fence ready 7. sap set sack sat 7. cape case cake hate 8. daily kneeling feeling 8. pulse fall false fault . dealing 9. herb verge heard urge 9. part heart art arch 10. escape mistake estate 10. intent intense content state intend 11. dip bit disc fit 11. palate palace pilot callous 12. muzzle muscle muffle mumble 12. soon soothe suit sue 13. stricken chicken thicken 13. state mistake estate escape sicken 14. feel heel field deal 14. knave named main name 15. gig big Dick dig 15. ration racial Rachel ratio 16. tent tend ten pen 16. very bearing berry carry 17. bird heard third thorough 17. monk mud month much 18. rabbit lavish ravish ravage 18. dealt felt belt bell 19. clam flange plan planned 19. shoe choose too chew

Score:_____ Score:_____ APPENDIX F 107

Wechsler-Bellevue Vocabulary

Define the following words in an adequate, "diction- ary" style, without too much elaboration or detail

1. Nuisance 20. Belfry 2. Pur 21. Recede

3. Cushion 22. Affliction 4. Shilling 23. Pewter

5. Gamble 24. Ballast 6. Bacon 25. Catacomb

7. Nail 26. Spangle 8. Cedar 27. Espionage

9. Tint 2 8 . Imminent 10. Armory 29. Mantis

11. Fable 30. Harakiri 12. Brim 31. Chattel

13. Guillotine 32. Dilatory 14. Plural 33. Amanuensis

15. Seclude 34. Proselyte 16. Nitroglycerine 35. Moiety

17. Stanza 36. Aspetic 18. Microscope 37. Flout

19. Vesper 38. Traduce APPENDIX G 109 INSTRUCTIONS FOR.LETTER-GUESSING

Step 1 . On each of these cards is a phrase taken from newspapers so that there are no technical or unusual, words.. They are from the middle of sentences, however, father than the beginning or end. Each begins with a whole word, but does not necessarily end in a complete word. (Show sample phrases of both kinds: complete and incomplete forms.) One half of the letters have been deleted at random.

Step 2. On the first five cards you are asked to make one guess for each dash. A dash may indicate either a letter or a space; a space always means a space between words. (Indicate on sample.) Write down your guess just below the dash; tell me what it is as you write it. I will tell you the right letter. Fill that in the space so that you can see the correct words. You will be timed on this, but your right and wrong scores also count, so do not sacrifice correctness for time. Some people guess just by letter, others try to. work out the whole phrase. Do whatever seems to work better for you. Any questions? 110 Step

On the next five cards the task is the same, except that you will have a maximum of five guesses per letter. Write down each one like this, (show sample), and I will tell you it it is right or wrong.. Fill in the right letter after you guess it, or after the fifth wrong guess, when I will give you the-answer* Ill MJETEATED PHRASES FOR LETTER GUESSING

1. t h b c 0 w k/

2. r r n o 6 W

3. _ r e V —. a _ ... 0 f/

r e _ a _ n _ c _— 0 o/

5. e m— e _ mm y mmm, 0 /

6. h a d 1 mm mm mm b mm mm 1 o/

7. w a f 1 g e t/

8 . h _ _ n g mm mm mm s i 0 n/

9. s — — — — y s a — e e/ H o • e e n e t r i/

KEY

1. the back to work 1 guess per dash 2. are trying to cut 11 3. for every day of " regain control of "

5. not be ready to

6. handle the ballots 5 guesses per dash 7. was far larger than " 8. the long version 11

9. seven days a week " 1 0 . been able to bring 11 APPENDIX H TABLE IX 113 INDIVIDUAL SCORES ON OSPE, WECHSLER, AND TESTS OF HEARING FOR SPEECH

SUBJECT OSPE OSPE-RC WECHSLER SRT PB WC IQ-

001. 44 2 91 30 72 44 002 2 3 85 20 76 48 003 4 6 98 26 o9: .82 49 004 9 104 22: 74 50 005 5 21 85 21 82 006 8 17 98 28 86 k9P° 007 6 9 91 30 76 4o 008 4 17 106 28 76 46 009 4 1 110 19 76 53 010 8 21 104 21 ■ 84 55 101 17 40 110 26 80 51 102 17 29 117 26 76 39 103 .18 5 99 25 84 48 104 10 9 98 16 78 54 105 12 14 104 21 86 54 106 18 11 98 27 70 58 107 10 12 115 18 80 55 108 15 14 104 29 82 33 109 10 2P 91 24 82 110 19 14 100 26 82 4l.P1 201 21 9 91 28 84 42 202 21 32 104 25 86 203 26 14 107 19 82 204 26 60 104 30 84 4o 205 21 32 97 25 82 49 206 26 63 98 26 86 48 20 7 26 32 110 26 74 74 208 23 21 121 29 82 51 209 21 36 104 19 88 51 210 28 21 110 I8 90 51 301 33 P2 123 27 80 48 302 33 48 104 18 86 53 303 39 31 110 21 76 52; 304 35 52 98 15 90 305 39 52 113 27 80 49P8 306 33 44 117 25 82 48 307 33 ,2* 104 22 76 57 308 37 48 110 21 74 60 309 37 39 110 21 86 310 33 32 121 21 78 SUBJECT ' OSPE OSPE-RC WECHSLER SRT PB MC

i+Ol k7 44 104 26 82 4-6 t o 44- 36 110 28 82 4-8 t o 42 t o 115 24 76 56 4-04- 45 60 110 23 82 38 ^05 4-7 60 104 30 78 33 4-06 k2 36 104 22. 76 58 *+07 42 29 119 22 92 57 4-08 4-3 58 110 17 88 55 t o 4-3 k7 115 22 88 59 4-10 46 67 110 29 76 37 501 54 36 110 27 78 57 502 75 121 21 90 57 503 54 56 123 21 78 50 504- 54 60 117 29 88 4-1 505 57 60 117 22 88 61 506 56 Qk no: 21 92 60 507 56 75 115 25 80 52 508 55 25 115 29 88 45 509 58 56 113 25 88 55 510 59 66; 104 25 84 52 601 63 70 113 21 84 63 602 61 60 104- 20 56 60 603 63 72 n o 16 80 57 604- 69 77 12 7 20 88 49 605 68 63 115 24 74 53 606 63 56 104 25 82 52 607 69 66 117 25 78 59 608 69 70 112 22 84 61 609 64 k8 110 21 78 52 610 6k 72 104- 24 82 53 701 78 75 123 21 94- 57 702 70 66 123 24 74 51 703 7k 72 106 34 78 34 704- 75 70 115 19 86 60 705 75 82 130 16 84 65 706 78 70 110 22 82 60 707 75 72 121 16 92 62 708 73 t o . 115 21 76 60. 709 73 63 110 18 82 5k 710 7k 71 121 23 80 4-5 U\ H H rooo H rOCXD OWO b \ CM 00 CO CM tN-O fOCM J N O H I N § u n u m o vo J- u n Un j - u m t n J - j- irvvo vo UnUnvo u n j-

OOOCMCOvOvOvOvOOOO O VOOO O -d " J-.d *v O _ d - O 0 0 O \0 0 0 0 Cv-C^OO CO 0 0 Cv- ONOOOO ONCO [> -0 0 0 0 0 0 0 0

U nItnh rOtN-vO O-vO H O ON VO o O OS H O -d* O ON OJ CMHCMHCMCMHCMCMCM HCMCMCMr—ICMCMCMCMCM co

Pd (>•[>.IrvovtN-H IS rO H lN m o - m o - m o 0 - 0 H m HrHi—IHCMCMCMCMCMH CM CM CM H CM H H m C M m i—IrHHi—I H H H H H H HHHHHHHHHH o

O i w VO IN VO CM ON CM O CM CM VO vo J - o o n e v e n t s ,o v o o o n P>4 00 0 0 0 OVOO O-CO OO 00 lev ON OVOO 0 0 ON a v t> - ON O n ON CO o

W Pl. H CNjdvJ- H^NCM J - O H UN CM H VO 0 0 U n c o ON ON ON CO 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 00 OnOnOnCJNOnOnOnonOnOn

H CM end: UnvO iS oo O n O H CM rOJ-UNvo O-00 O O OOOOOOOOOH OOOOOOOOOH oooooooooooooooooooo o o o o o o o o o o 116 TABLE X SUBJECTS' UNCONVERTED LETTER-GUESSING SCORES: TOTAL OF TEN PHRASES PER SUBJECT

Subject •Time RijSht Wrong Subject Time Right Wrona 001 191^ 101 1021. 2397 51 j S t 2 1110 52 79 2 21+15 60 70 2069 60 69 766 **7 113 1 2606 59 66 I 2032. 62 66 5 1750 60 67 5 3150 58 7k 6 1183 53 80 6 1576 58 80; 7 1069 5** 71 7 1M36 61 59 8 1565 60 62 8 2709 1+8 103 9 2519 57 83 9 1676 60 75 10 1870 55 79 10 1081 50 92 Total: 17655 558 757 19368 565 796

201 2017 52 108 301' 1196 52 82 2 181+7 55 68 2 3l8r 65 1+6 818 58 76 2925 72 1+2 I 787 52 91+ I 3267 53 90 5 859 51+ 82 5 639 57 7k 6 13*1 k7 105 6 1855 58 79 1168 63 71 7 933 57 63 1 781 55 73 8 2551 55 67 9 1192 55 73 9 1255 65 57 10 2162 55 83 10 1866 52 76 Total: 12972 51+6 833 19668 586 676

1+01 17**7 62 66 501 250^ & 81 2 1168 51* 73 2 2172 51* 90 111+5 60 67 860 i+8 90 I 1692 50 100 I 195** 1+9 98 5 2170 51 88 5 121*f 61+ 51 6 1905 60 73 6 835 58 78 3881 55 77/ 7 101+5 62: 60 679 55 75 8 1260 62 61 9 1361 53 79 9 66*+ 56 61 10 801 58 68 10 11+83 67 1+2 Total: 1651*9 558 766 12991. 571 712 117 Subject Time Right Wrong Subject Time Right Wrong

601 lOlfl 5b 8*f 7.01 1213 62 59 2 120*f 55 7.8 2 625 59 61 3 1113 55 67 3 1211 59 77 If 1726 61 63 b 19*f2 60 8T 5 2^05 65 55 5 1760 60 80 6 632 58 72 6 1Q95 95 7 1956 62 ,66 7 1868 63 65 8 971 57 8 739 60 71 9 982 53 81P 9 1685 6b 59 10 19 77 57 71. 10 9**1 57 66

Totals: 1^007 577 720 13019 592 71*+

801 90*f 56 69 901 1521 60 5b 2 6*f 2 1826 1725 ? 3 1*8 9b 3 69*+ 56 81 3 1513 52 89 If 1592 63 1*8 b 700 58 72 5 2277 60 69 5 868 60 60 6 1^10 65 55 6 1130 62 71 7 713 60 6b 7 1078 52 81 8 797 77 8 1**78 61* 1*6 9 602 5b 82 9 1273 57 67 10 1063 65 1*6 10 951 55 76 Total: 11777 596 6M4- 12338 568 710 T

118 TABLE XI INDIVIDUAL PURE TONE THRESHOLDS . IN CODED SCORES *

Subject Left Ear Right Elar 500 1000 2000 IfOOO 500 1000 2000 ^000

001 3 .3 3 2 0 1 2 2 1 2 2 2 0 * 2 1 0 2 3 2 3 1 1 2 3 3 2 b 3 2 2 0 3 2 3 2 5 2 2 2 0 2 2 1 0 6 2 2 2 0 *f 2 0 2 7 b' If 3 b 3 3 3 b 8 2 3 2 2 2 2 1 1 9 1 2 1 2 3 2 1 1 10 2 3 2 2 2 2 1 b

101 3 if 3 2 b 2 1 1 2 1 2 b 2 3 ’ ? V 3 3 3 3 2 0 2 b h 1 b 2 3 1 2 1 2 b 3 5 2 2 1 0 2 3 0 0 6 2 2 0 2 3 0 1 0 7 2 2 2 2 2 2 1 l 8-, 3 2 2 2 2 2 2 3 9 3 3 2 2 2 2 0 0 10 2 2 2 if 2 1 1 b

201 ' 2 2 2 1 2 0 1 1 2 2 1 1 0 1 2 0 0 3 2 2 2 0 2 If 0 0 b 3 3 2 3 3 3 1 1 5 2 2 b 2 1 2 b £ 2 2 1 2 1 1 1 1 7 b 3 >f 2 V »f b 0 8 2 3 2 1 2 2 0 0 9 3 3 2 1 1 2 1 0 10 2 2 1 3 1 0 1 0 301 2 2 2 1 9 2 0 0 2 2 2 ' 2 0 2 2 2 1 3 2 1 1 1 2 1 2 0 4- 2 2 0 1 1 1 2 1 5 1 1 3 2 1 2 3 2 * Code: 0 -10 db 5 db 1 - 5 11 2 10 » 2 0 » O n iH H O O rIOHHH OHOHOCMrlH O J- rH i—I O O O O i—1 1—I CM J" O O nOO O H noo O CM O J - OCMOOOOHH -d" f4 do HO OrHHOrH rlrlHrlOHHH H - d " i—li—I O O O H H H C M H rHCMHHHOOOOO H 4 CMrlOriH H nOCM O •— I -P CM X ! . MO •HO CM C\JO CM O CV CM H CM H-CM CM CM CM CM O n o CM CM H CM CM CM n o CM rH-CM iHCMCMCMCMOiHCM H - d * H CM CM CM CM CM nOCM H O rH o ;-i O CM n o CM n O O H H CM CM H - C O CM H CM CM OOOCMCMHCMnOnOCMno pH CM CM CM CM H - d * O H H UN CM CM noo O H CM H-d-

O U O O O O CM rH HCMHCMOOCMCM H J- H CM O O O i CM O CM CM Cd O r + O CMCMOOCMOrHO H d O J - O CM CM H CM H WJ- -P o «hffi O H H C M H H H J -C M H C M CM CM n o CM J - O CM H O O CM CM CM CM no CMHCMCMOOCMCMCMiHrH O CM noo O H O CM HCM H CM O O CM CM CM r O O CM CM n o CM n o CM n o no CM no rH no CM nO H CM no CM CM no CM CM CM H CM nO H H O CM O CM n o CM CM CM C M J- CM CM rH O O n r O C M j - O CM CM CM) CM n o CM-d* nO CM CM H CM CM CM CM no-j-CM CM CM CM CM' CM CM CM CM CM HC M CM CM n o n o n o CM n o CM n o n o CM \TN

•P O CD VO O-CO O N O H CM COJ-lTVO IN-OO ONO H CM n0_4- U0\O tNOO ON O H CM no,d-tCNvO Csco O n O H CM nod- icvvo IN-00 o n O X»•na '1O . , n y H j? - H R H CO Left Ear Right Ear Subject 500 1000 2000 4-000 500 1000 2000 *1-000

801 4- 4- 3 2 3 2 1 0 2. 2 2 » 0 0 1 2 1 0 3 2 2 2 1 2 1 1 0 4- 2 2 0 0 2 1 0 0 5 2 2 1 2 2 2 1 3 6 2 3 2 1 2 *f 0 0 7 2 2 2 2 1. 1 1 2 8 . 2 2 0 0 0 1 1 0 9 2 2 2 1 2 2 1 0 10 3 2 1 1 5. 3 2 2 901 2 2 2 2 2 2 1 1 2 3 3 2 1 2 2 1 0 3 2 2 2 1 2 3 2 1 4- 2 2 1 0 1 2 1 -1 5 2 2 2 0 1 2 1 0 6 4- 3 2 2 2 3 0 1 7 2 2 0 0 2 3 0 4- 8 2 2 2 2 3 1 1 4- 9 4- 2 1 2 3 2 1 0 10 2 2 2 1 2 2 1 1 APPENDIX I TABLE XII COEFFICIENTS OF CORRELATION, MEANS, AND STANDARD DEVIATIONS - . . USED IN THE MULTIPLE.CORRELATIONS.. . . x2 X1 x3 xl+ x 5 *6 x7 *1 y2 y3 OSPE W B L G 2000 5oor 1000 1*000 SRT. PB MC x-jOSPE .721 .312 -.19** -.055 -.079 -.176 -.235 .211+ .320 X2 W B .252 -.115 -.080 -.070 —.1^6 -..181+ .237 .253 x^ L G .139 .17*+ .096 .008 -.200 -.057 .316 x^ 2000 .311 .356 A79 .299 -.302 -.311* x 5 500 .263 .270 .186 -.016 -01+3 X5 1000. .17*+ .171 -.068 -07^ Xy 1+000 .118 -.072. -.219 Mean 1+9.73 111.28 1^9.25 2.76 1+.23 1+.08 2.29 22.95 81.9*+ 52.21+ deviation 28.77 10.06 21.16 1.69 1.1*0 1.36 2.05 *+.11 5.83 7.25 122 123

TABLE XIII MATRIX AND INVERSE MATRIX USED FOR MULTIPLE. CORRELATION

OSPE w b L G 500 1000 2000 4000

OSPE 1.000 .721 .312 -.055 -.079 -.194 -.176

WB .721 1.000 .252 -.080 £.070 -.115 -.146 L G .312 .252 1.000 .174 .096 .139 .008 500 -.055 -.080 .174 1.000 .263 .311 .270 1000 -.079 -.070 .096 .263 1.000 .336 .174 2000 -.194 -.115 .139 .311 .356 1.000 .479 4000 -.176 -.146 .008 .270 .174 .479 1.000 OSPE 2.2592 -1.4985 -0.3634 -0.0406 0.0021 0.3065 0.0455

WB -1.4985 2.1052 -0.0695 0.1070 • 0.0378: -.1166 0.0646

L G -0.3634 -0.0695 1.1940 -O.1770' -0.0395 -.2095 0.0714 500 -0 ,04o6 0.1070 -0.1770 1.1969 -0.1954 -.1815 -.1923 1000 0.0021 -.0378 -0.0395 -0.1954 1.1825 -.3629 0.0270 2000 0.3065 -0.1166 -0.2095 -0.1815 -0.3629 1.5425 -.5881 4000 0.0455 0.0646 0.0714 -0.1923 0.0270 -.5881 1.3458 124- TABLE XIV PREDICTION EQUATIONS USING ESTIMATED RAW SCORE COEFFICIENTS

yi = -.0l32Xl -.o o 91X2 -.04-55x3 4 -6988xif 4.4037x * .1834-x6 -.1705X7 . 2 7 .4-121

yg = .0109x2 +.1208x2 -.0272x3 -1.1936xlf. +*3729x ^ 4-«l802X g +• 2927xy + 72.3264- y3 *^313x2 +*0333x24-. 104-2x3 v—-1.3664xij. +* 104-8X0 +*l4-23xg -.1780X r, + 34-. 5810 l 125

AUTOBIOGRAPHY

I, Ethel Foladare Mussen, was born in Los Angeles, California, April 13, 1921. I received my secondary school education in the public schools of Los Angeles. My under­ graduate tr&ining was obtained at the University of Cali­ fornia at Los Angeles, from which I received the degree of Bachelor of Arts in 1951. While an undergraduate,I was laboratory assistant in speech for the English for Foreign students program from June, 1950 to August, 1951. From the Ohio State University, I received the degree of Master of Arts in June, 1952. While in residence at The Ohio State University, I was granted a Scholarship in Audiology by the Ohio State Department of Health. For the next two academic years, I was granted a Fellowship, in Audiology while complet­ ing the requirements for the degree of Doctor of Philosophy. From June 4 to August 20, 1953, I "served as Instructor of Speech and Hearing Therapy at Marshall College in Huntington, West Virginia.