THE EFFECTS OF DURAUON. FREQUENCY, AND LOUDNESS UPON THE REFROBUC‘HGN 0F TEMPORAL INTERVALS B? SENSORfi-HEURAL EEARWG EMPAIRED SUBJECTS 'Ihesis for the Degree of Ph. D. MICHQGAN STATE UMVERSITY Ray fl» an Hartésauer 1957 ' mm LIBRARY Michigan Stab University This is to certify that the thesis entitled THE EFFECTS OF DURATION, FREQUENCY, AND IDU'DNESS UPON THE REPRODUCTION OF TEMPORAL INTERVALS BY SENSORI -NEURAL HEARING IMPAIRED SUBJECTS presented by Roy Elden Hartbauer has been accepted towards fulfillment of the requirements for Ph . D . degree inm— DateJehmanLJBJfiJ— L 0-169 2w. “ "”733?" ABSTRACT THE EFFECTS OF DURATION, FREQUENCY, AND LOUDNESS UPON THE REPRODUCTION OF TEMPORAL INTERVALS BY SENSORI-NEURAL HEARING IMPAIRED SUBJECTS By Roy Elden Hartbauer The study of time and the perception of it has occu— pied the attention of scientists for many years. Both ob- jective and subjective research has been done on time per- ception of persons with normal hearing with somewhat contra- dictory findings. The purpose of this study was to investigate the ef- fects of duration, frequency, and loudness upon the ability of sensori-neural hearing impaired subjects to reproduce tem- poral intervals. Tones of 500, 1000, and 2000 cycles per second were presented at 60, 70, and 80 phon levels for l, 5, and 9 seconds. Each of the 27 possible combinations of these parameters was placed in random order on magnetic re- cording tape and presented ten times randomly to each of the five subjects who sustained a mild sensori-neural hearing loss. The psychophysical method of reproduction was employed. Each subject attempted to reproduce the duration of the stim- uli by depressing a telegraph key. During the attempt he heard again a sound of the same frequency and intensity as the stimulus sound. The puted b}' d tween the the actual was the me nations. It ‘ that there 0f the per: the Possib; iance, It the reprod; Significant 93' The ratio, —r , to be used in the analysis, was com- puted by dividing the difference-time (the difference be- tween the stimulus duration and the response duration) by the actual duration of the stimulus. The subject's score was the mean of 10 reproductions for each of the 27 combi— nations. It was ascertained by the F-Max test computations that there was a lack of homogeneity of variance for some of the parameters. The results, however, did not preclude the possibility of treating the data by an analysis of var- iance. It was found that the only variable that affected the reproduction was duration. Specifically, there were significant differences between the pairs of durations of l and 5 seconds, 1 and 9 seconds, and 5 and 9 seconds. No effect was found for the frequency and loudness variables. There were no interactions between or among the three pa- rameters. On the basis of these results it was concluded that within the limits of this study, reproduction of temporal intervals by sensori-neural hearing impaired subjects is affected by the duration of the stimulus. One-second stim- uli are overestimated, whereas five- and nine-second stim- uli are slightly underestimated. Manipulation of the fre- quency and loudness parameters did not affect the ability 0 m m (D :1 m 0 H duration c form 51:11] #4 . tron of tr Re: basis of t of sensori-neural hearing impaired subjects to reproduce the duration of stimuli. Subjects with sensori-neural hearing impairments per- form similarly to those with normal hearing in the reproduc- tion of the duration of acoustic stimuli. Recommendations for further research were made on the basis of the results of this study. © COpyright by ROY ELDEN HARTBAUER 1967 CFC in p, THE EFFECTS OF DURATION, FREQUENCY, AND LOUDNESS UPON THE REPRODUCTION OF TEMPORAL INTERVALS BY SENSORI-NEURAL HEARING IMPAIRED SUBJECTS by Roy Elden Hartbauer A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Speech 1967 LIST OF TABLE II. III Iv, INTR 'U I Q 'U H 3 rt: '(3 r1 0 U (D ff . REVII Intr: Th80z Devel Prob; Psych IndiV PErce; Summa] SUBJEC Sublec InStru; prOCed.~ RESULT" ReSults DiSCUSSi TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES Chapter I. II. III. IV. INTRODUCTION . . . . . . Purpose of the Study Importance of the Study Definitions REVIEW OF BACKGROUND LITERATURE. Introduction Theories of Time Perception Development of the Concept of Time Problems in the Study of Time Perception Psychophysical Methods Employed in the Study of Time Individual Differences Perception of Time by Hearing Impaired Subjects Summary SUBJECTS, INSTRUMENTATION AND PROCEDURES Subjects Instrumentation Procedures RESULTS AND DISCUSSION . Results Discussion Page mum 11 11 12 21 24 3O 38 44 4s 48 48 49 51 '60 60 68 Om o L; H i '0 r1 3 BIBLIOGE APPENDI} APPENDIX APPENDIX APPENDIX APPENDIX V. SUMMARY AND CONCLUSIONS . . . . . . . . . Summary Conclusions Implications for Further Research BIBLIOGRAPHY . . . . . . . . . . . . . . . . APPENDIX A APPENDIX B APPENDIX C APPENDIX D APPENDIX E Difference Between Actual Stimulus Duration and Subject Response Difference Time Ratio Text of Telephone Solicitation Letters From Research Persons Letter to Research Persons ii 74 74 77 78 82 93 99 105 107 109 Table ‘1 - Sam“ Anal Comp the j in T: Criti REPrC Compu Stimu Table LIST OF TABLES Page The Averaged Interpolations for the Intensity Equivalent of Phons Given in Decibels re 0.0002 Dyne/CMz . . . . . . . . . 52 Variances Used to Compute the F-Max Tests for Homoscedasticity for Duration, for Frequency, and for Loudness . . . . . . . . . 62 Summary Table for the Factorial Design Analysis of Variance . . . . . . . . . . . . 63 Computed Means and Standard Deviations of the Reproduction of Each Stimulus Duration in Terms of Difference-Time . . . . . . . . . 65 Critical Difference Between the Means of Reproduction Time . . . . . . . . . . . . . . 67 Computed Means of Subjects Responses to Stimuli Durations . . . . . . . . . . . . . . 71 iii Bloc 1. m. w. m x all e. E s R 3. H.953? 7r. ,4! _ It. LIST OF FIGURES Block Diagram of Recording Apparatus . Block Diagram of Instrumentation for the Experimental Sessions . . . AEI; Plotted as a Function of Duration Showing Means and Standard Deviations of Reproduced Temporal Intervals iv Page The :oblens o erences to EU the co: Sage and me Cm PIOble: views the s sees the ti the PhYSici Vice, and 1: time, Gill psychOlogls. what people Frais CHAPTER I INTRODUCTION The study of time existed before the study of the problems of the acoustically handicapped. The earliest ref- erences to man reveal his concern over the nature of time, and the confusion and apparent contradictions over its pas- sage and measurement. The individuality of man has added to the problem. Each person, from his peculiar discipline, views the study of time in a unique way. The work-a-day man sees the time-clock, the athlete sees time as a competitor, the physicist and the astronomer see it as a measuring de- vice, and the philosopher is interested in the nature of time. Gilliland, Hofeld, and Eckstrand1 point out that the psychologist is interested in the response of peOple to time. What people do with time is a concern of the sociologist. Fraisse2 states that philosophers studying the 1A. R. Gilliland, Jerry Hofeld, and Gordon Eckstrand, “Studies in Time Perception," Psychological Bulletin, XLIII (March, 1946), p. 162. 2Paul Fraisse, The Psychology gj_Time, Trans, Jennifer Leith (New York: Harper and Row, Publishers, 1963), p. 3. origin c tion of changes, rhythmic rd]. phe: measure: IOtatiQn of the r: 2 origin of the idea of time have concluded that the percep- tion of time comes from awareness of change. He asks: What changes, our sensations or our thoughts? The answer to this question differs, depending upon the sensory facilities of the person who is to experience time. Apart from the sensation of time, the mechanical or rhythmical passing of time has been well detailed by natu- ral phenomena and the invented devices of man. The natural measurement systems mark the yearly cycle by the earth's rotation around the sun, the monthly cycle by the rotation of the moon around the earth, for those of a religious bent the Sabbath cycle by the passing of seven days, and the daily cycle by the earth's rotation on its axis. It should be noted, as pointed out by Bell and Bell,3 that the wobbling of the earth on its axis as it travels in its slightly eliptical orbit around the sun, causes some un- certainties of the rotational cycles. The invented devices of man, such as the clock in its myriad forms and the calendar, are geared to coincide with the markings of the natural phenomena and to divide it into stated segments, such as minutes and seconds. Since 3Thelma Harrington Bell and Corydon Bell, The Riddle g§_Time (New York: The Viking Press, 1963), pp. 73-74. parts in Technolo; the vibra the nucle behave 1; 0f the 0: tion beer HOW be OI‘ Wi same rega pretation Other ham here time a "CODCep experienc Ea 3 1949, ammonia clocks have been employed by the Bureau of Standards which have a calculated error of only two to four parts in one billion. At the Massachusetts Institute of Technology, Zacharias4 developed a clock which makes use of the vibrations of cesium atoms as a master governor. Both the nucleus and the outermost electron of the cesium atom behave like minute spinning magnets, each in the force field of the other. Zacharias has calculated that had his inven- tion been "ticking away" since the time of Christ, it would now be only one-half second fast or slow. With these mechanical devices the results are the same regardless of who Operates the equipment. The inter- pretation of the readings is essentially identical. 0n the other hand, psychological measurements of time differ, for here time exists subjectively. Sturt5 suggests that time is a "concept which is built up through individual and racial experience." Early man measured time in terms of events and/or tasks. According to the Biblical record, time was measured 4Ibid.. p. 70. 5Mary Sturt, The Psychologygf Time (New YOrk: Harcourt Brace, and Company, 1925), p. 1. - ,-_ 1-..-- a-WJP .- 'II"|!| I , by "the 6 points on time in t duration. Ex 711% of t sonal ada EXiSt as Contents the effec: tiOn Of t 0f the ra: perceptioz teIVal mu: aCtiVitieg Passage fc 4 by "the evening and the morning were the first day."6 Cohen7 points out that today primitive people customarily measure time in terms of social events and tasks, not in units of duration. Experimental factors, the tempo of life, the perspec- tive of the proximity of the event to the present, and per- sonal adaptability bespeak that many individual "times" exist as separate subjective entities. The effects of the contents of the intervals between two events, as well as the effects of the events themselves, influence the percep- tion of time. Bell and Bell8 note that the metabolic rate of the race, society, and the individual influences the perception of the passage of time. It appears that the in- terval must be filled with interesting, pleasant, or amusing activities and that little attention must be given to its passage for time to seem short.9 6Genesis 1:15. 7'John Cohen, "The Experience of Time," Acta Psycho- logica, X (1954), p. 211. 8Bell and Bell, 92, cit., Chapter 6. 9Marianne Frankenhaeuser, Estimation g£_Time (Stock- holm: Almquist and Wiksell, 1959), pp. 14-15. jective with the With hi: of the 5 seems to "Are the ception mary DEC, 5 Within the limits of human experience, Sturt10 has noted that there are great differences in the power to per- ceive time and to deal with temporal ideas. Furthermore, within each person is the existence of many individual sub- jective times. Some of these are adjusted to synchronize with the times of others to facilitate man's co-existence with his fellow man. With the focus of attention directed to the problem of the acoustically handicapped and his complaint that life seems to lose its on-going character,11 the questions arise: "Are there some elements of sound which affect man's per- ception of time?" "Can some element be isolated as of pri- mary necessity for the accurate and/or consistent perception of the duration of filled intervals?“ Attention is placed, therefore, on the interdigita- ting of concerns for the passing of time as a subjective entity, the reception of auditory stimuli to influence times passing, and the distortion of that perception by the alter- ing of the reception of the auditory stimuli as experienced 10Sturt, 22, cit., p. 10. 111. J. Hirsh, R. E. Bilger, and B. H. Deatherage, "The Effect of Auditory and Visual Background on Apparent Duration," American Journal 9; Psychology, LXIX (December, 1965). PP. 561-574. by the l of sens: ration : 9393C33 only one tion in l l 2 3 4. In 1 and 21 RI Loudne MinIEUbliS c' H 19a“ Si by the hearing-impaired. PURPOSE OF THE STUDY The purpose of the study was to determine the effects of sensory-neural hearing loss on the perception of the du- ration of pure tone stimuli as a function of duration, fre— quency, and loudness. Deal12 found that duration was the only one of these variables that affected temporal percep- tion in persons with normal hearing. The questions asked at the outset were as follows: 1. In Does the duration of a tone affect the ability of a person with a sensori-neural hearing im- pairment to reproduce a time interval? Does the loudness of a tone affect the ability of a person with a sensori-neural hearing im- pairment to reproduce a time interval? Does the frequency of a tone affect the ability Of a person with a sensori-neural hearing im- pairment to reproduce a time interval? Are there any interrelationships among loudness, frequency, and duration that affect the ability of a person with a sensori-neural hearing im- pairment to reproduce a time interval? an attempt to answer these questions, the 12Leo V. Deal, "The Effects of Duration, Frequency, and Loudness Upon the Reproduction of Temporal Intervals," (Unpublished Ph. D. dissertation, Department of Speech, Michigan State University, 1965). 7 following null hypotheses were formulated for testing: 1. One itation or There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 1 second, 5 seconds, and 9 seconds. There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 500 Cps, 1000 cps, and 2000 cps. There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 60 phons, 70 phons, and 80 phons. There is no significant interaction between du- ration and frequency in the performance of per- sons with sensori-neural hearing impairments in reproducing temporal intervals. There is no significant interaction between du- ration and loudness in the performance of per- sons with sensori-neural hearing impairments in reproducing temporal intervals. There is no significant interaction between fre- quency and loudness in the performance of per- sons with sensori-neural hearing impairments in reproducing temporal intervals. There is no significant interaction among dura- tion, frequency, and loudness in the performance of persons with sensori-neural hearing impair- ments in reproducing temporal intervals. IMPORTANCE OF THE STUDY of the concerns of the persons working in habil- rehabilitation of the hearing impaired is in ascertaining what the hearing impaired person can hear as sFmF I well as ability Densati stimuli been co neural Studies tory St ments. QiVe ri tdin a a Step Of dura to Fete. implice. 8 well as what he cannot hear. Knowledge of the hearing ability largely dictates the steps to be detailed in com- pensating for the handicap. Many studies have dealt with thresholds for auditory stimuli in normal hearing persons. Still other research has been concerned with the thresholds of persons with sensori- neural hearing impairments. There have not been, however, studies dealing with the perception of the duration of audi- tory stimuli in persons with sensori-neural hearing impair- ments. There must be a discovery of the conditions that give rise to variations in the experience of time to ascer- tain a causal analysis of time perception.13 This study is a step in ascertaining whether or not any of the parameters of duration, frequency, and intensity are causally related to perception of duration. The findings may have important implications for further research, clinical audiometry, and habilitation or rehabilitation procedures. DEFINITIONS Definitions of terms that are commonly used in re- ports of research on time and in this discussion follow: 13Aldeno. weber, "Estimation of Time," Psychological Bulletin, xxx (March, 1933), p. 235. #“77 sidered and rep fers to sound v; IL...‘ 9 Time. In this paper the term "time" will be con- sidered as a measured duration employed by the experimenter and reproduced by each subject. Duration. The definition of "duration" used in this study is that period of time during which anything lasts. Freggency. For this study the term “frequency" re- fers to the number of oscillations per unit of time of the sound vibrator, expressed in cycles per second. Loudness. In this paper the term "loudness" refers to the sensation level of auditory stimuli. The unit of measure is the phon, defined as the intensity required to produce the sensation of equal loudness to a 1000 cps tone of a specific intensity. The phon and the decibel are by definition the same at the frequency of 1000 cps.14 Indifference interval. For this study the indiffer- ence interval will be the same as for the study by Deal:15 "taken as the point which the ratio of the average differ- ence-point divided by the actual duration is equal to zero. It is the point where overestimation changes to underestima- tion." l4Hayes A. Newby, Audiology (New York: Appleton- Century-Crofts, 1964), pp. 166-167. 15Deal, 92, cit., p. 16. .1 '4 r gv'y 1V guti'o'. “' val, th '1‘ di fere: nition 1 to the 1 the var: 10 Time-order errors. As with the indifference inter— val, the time-order errors will have different meaning when different psychOphysical methods are employed. The defi- nition by Woodrow is used for this paper: "The effect due to the temporal order of presentation of the standard and the variable."16 Posigive e££g£_will be used when the stim- ulus interval is gyegestimated, i,e, when the subject's re- production is too long. Negative e££2£_wi11 be used when the stimulus interval is ungegestimated, i,e, when the sub- ject's reproduction is too short. Sensori-neural hearing impairment. For the purpose of this study, the term "sensori-neural hearing impairment" will refer to any shift of greater than 15 decibels (re. audiometric zero) of thresholds for pure tone sounds, 500, 1000 and 2000 cycles per second, due to lesions in the auditory tract central to the oval window of the cochlea. There will be a negligible difference between the air con- duction and bone conduction thresholds which could indicate a conductive element in the hearing impairment. 16Herbert WOodrow, "Time Perception," Handbook 9; Experimental ggvcholoqy, ed. S. S. Stevens (New York: John Wiley and Sons, Inc., 1951), p. 1225. CHAPTER II REVIEW OF BACKGROUND LITERATURE INTRODUCTION While some researchers have approached the study of time perception from an empirical standpoint by direct ex- perience or observation alone, others have approached it experimentally. Both have arrived at theories of the per- ception of time. The diversity of approach has resulted in a diversity of theories and numerous apparent contradictions. It is evident that the perception of time is not a constant thing. Excellent reviews of literature on time perception include those by Gilliland and Humphreys,17 Triplett,18 17A. R. Gilliland and Dorothy Humphreys, "Age, Sex, Method, and Interval as Variables in Time Estimates," JOur- nal 9£_Genetic Psychology, LXIII (September, 1943), pp. 123- 130. 18Dorothy Triplett, "The Relation Between the Physi- cal Pattern and the Reproduction of Short Temporal Inter- vfils: A Study in the Perception of Filled and Unfilled Time," §§ycholoqica1 Mbnoqraphs, XLI (1931), pp. 201-265. 11 ‘ VA 9;}. raisse. bl the inte errors‘Z used in 19 20 21‘ 225 23 164‘172 12 19 20 21 Fraisse, Woodrow, and Weber. The study of the nature of time, which is a concern of philOSOphy, also became a concern of psychology. With both disciplines, research on time study moved to the lab- oratory during the nineteenth century, where the concerns of early research included the effects of the content of the interval, the application of Weber's Law, and constant errors.22 Research on these gave bases for other approaches used in the study of time. THEORIES OF TIME PERCEPTION One of the earliest theories of time perception sug- "23 This included an internal, $22: gested a "time sense. biological or physiological, clock mechanism. Some of the later theorists maintained that time perception is some phase of the "self" which is uniquely the individual. Different forms of temporal experience suggested by 19Fraisse, 923 cit., pp. 1-343. 20Woodrow, "Time Perception," pp. 1224-1236. 21Weber, gpe cit., pp. 232-252. 22Fraisse, 92, cit., pp. 5-9. 23Gilliland, Hofeld. and Eckstrand. 22o si_t~ pp. 164-172. ”r.~ r» leaiy tn If") c . Omprehe Elent Of T‘J’plCal 133: w’) 27. 13 Cohen24 are: duration: sequence: pastness, the feeling of what has gone before: nostalgia, the changing effect when experiences recede into the past: sinceness, the feeling that time has elapsed since the occurence of an event: and orientation toward the future. It must be noted that time perception varies within an individual as well as varying from one person to another.25 Theories of time perception seem to fall into five primary divisions: 1. Time is perceived by a central nervous system mechanism. 2. A temporal clock mechanism provides a "time sense." 3. Time is perceived by bodily rhythms. 4. The amount of change determines the percep- tion of time. 5. Duration has a "unity of organization."26 Central Nervous System Mechanisms. Fraisse gives a comprehensive review of the theories that explain the judg- 27 ment of duration on the basis of the brain mechanism. Typical of these theories is this one by James: “...each 24JOhn Cohen, "The Experience of Time," Acta Psycho- logica, X (1954), pp. 208-209. 25Sturt, 92, cit., p. 147. 26Deal, 92, cit., p. 147. 27Fraisse, QB. cit., pp. 95-105. ‘ ‘5”‘(5'17 ing to cumstan more {a l4 stimulus leaves some latent activity behind it which only "28 That is to say, there is some gradually passes away.. hold-over from the preceding stimulus while we are respond- ing to the present stimulus. Especially under certain cir- cumstances and conditions, some of these processes have a more rapid decay time than do others. In support of this type of theory, Frankenhaeuser29 suggests that the second of two successively presented sounds of equal intervals will be judged as being longer because of the fading trace of the first one. This would be particularly true with a short interval between the two stimulus sounds. The electrical gradient in the brain field deter- mines the physiological process of successive comparison, according to Postman.30 He states that the excitation of a sense end-organ causes a disturbance of equilibrium in the brain field. This, in turn, leaves a trace, the after- effects of which will in time fade or "sink," and the 28William James, The Principles p§_§§ycholoqv (New York: Dover Publications, Inc., 1950), pp. 634-635. 29Frankenhaeuser, pp, cit., p. 19. 30Leo Postman, "Time-Error as a Function of the Method of Experimentation," American Jburnal p§_Psychology, LX (January, 1947), pp. 101-108. ”if trace t} esis the enphasiz ism. N1 brain as its. As theory WI“. this thee Chol091Ca Could Cla: A s HehYPOthe 15 longer the interval between the stimuli, the less residual trace there will be to affect the second stimulus.31 Experiments by Nichols32 seem to support the hypoth- esis that time is perceived by memory images. His results emphasize that memory images depend upon certain rhythmic habit processes of our nervous system and our bodily organ- ism. Nichols does not identify any specific part of the brain as responsible for the memory of these rhythmic hab- its. As an example of those advocates of the memory-image theory who do not agree with others, Angell33 believes that this theory has had a definitely negative influence on psy- chological research. Still other researchers, e,g, Edgell,34 could claim no experimental results to support this theory. A slightly different approach was taken by Creelman. He hypothesized that perhaps "a 'counting mechanism,‘ a 31Frankenhaeuser, pp, cit., p. 19. 32Herbert Nichols, "The Psychology of Time," Ameri- can Jburnal pf Psychology, IV (April, 1891), pp. 102-107. 33F. Angell, "Discrimination of Clangs for Differ- ent Intervals of Time," American JOurnal p§_gsycholoqy, XII (October, 1909), p. 79. 34Beatrice Edgell, "On Time Judgment," American JOurnal p£_Psycholoqy. LLV (July-October, 1903), pp. 169- 170. 16 simple accumulator, could store neural pulses in reverbera— tory circuits, or for that matter, store an electrical charge due to a chemical process."35 The Temperal_glppk Mechanism. As researchers have attempted to explain time perception, they have speculated that there may be an internal clock that would be a time- sense as surely as there are other senses even though, as presented in Mach's theory, time perception is a general sense while the others are specific senses. It employs the specific senses.36 Following their noting that the midbrain controls all the main periodic rhythms such as hunger, thirst, sleep, and sex needs, some researchers have considered the mid- brain as the temporal clock. It may be possible, there- fore, that these vegetative processes may act as a basis 37 for the experience of time. In light of recent research, few persons still 35Carlton Douglas Creelman. "Human Discrimination of Auditory Durations" (Unpublished Ph. D. dissertation, Department of Psychology, University of Michigan, 1960), p. 47. 36Fraisse, pp, cit., pp. 80-81. 37Ibid., p. 171. J l.4 .'- u'- mainta; time is able t: esized this p: some a: tual pr man is may be, the min 17 maintain that there is a special "time sense;" that is, that time is something which is experienced, or that a person is able to relate himself to clock time. Bartley has hypoth- esized that the body processes and sensory mechanisms make this possible.38 Bodily rhythms. Noting that animals seem to have some ability, not based on any symbolic device nor intellec- tual process, to estimate duration, Fraisse39 believes that man is capable of estimating time on a biological level. It may be, he states, that the biological influences work with the mind to permit surprising accuracy of judgments. MacDougall,40 Opposing the special time-sense theory, points out that subjective standards of measurement are de- pendent upon physiological changes. He suggests that vari- ations in the tension of sense organs form the basis for the judgment of short durations while the rhythms of res- piration determine the estimates of longer duration. Nichols,41 who does not accept the bodily rhythms 388. Howard Bartley, Principles p; Perception (New York: Harper and Brothers, 1958), p. 69. 39Fraisse, pp, cit., p. 62-63. 4ORobert MacDougall, "Rhythm, Time and Numbers," WMQIESEhOQqL XIII (January. 1902), p. as. 41Nichols, pp, cit., p. 106. — theory. ‘~1- swing . of dura Chan96s Way We l8 theory, points out that breathing, pulse-beat, and leg swing have all been suggested as factors in the estimation of duration. He sees no reason why any one unconscious process should dominate as a standard more than another. Neither did Renshaw's42 eXperimental results support a theory of time perception based on kinesthetic cues. His subjects, who sat still and alert, made better judgments than did those who made any physical movement. Ampunt p; Change. It has been advanced by some that changes in both bodily processes and external stimuli serve as cues for the perception of duration,43 Sturt44 believes that we experience duration indirectly, as opposed to the way we sense taste, touch, or smell. Fraisse believes that the body, under the influence of physiological changes, becomes a physiological clock to furnish cues for time perception. On the premise that per- ception of duration is based on successive changes, Fraisse 42Samuel Renshaw, "An Experimental Comparison of the Production, and Auditory Discrimination by Absolute Impres- sion of a Constant Tempo," Psychological Bulletin, XXIX (November, 1932), p. 659. 43Bartley, pp, cit., p. 69. 44Sturt, pp, cit., p. 8. my i-W’ - .‘ stated crease effect ness 3: the in: DISCUSS Of Chan the per some ph ing or . He main. dUratiOI 1 Pass bef Other ha \ 4. 4c a ti ’ onis n 1936) . m5 48. 19 stated the law, "Any factor which contributes toward an in- crease or decrease in the number of changes observed has the effect of lengthening or shortening the apparent duration."45 It appears that even attempts to blot from our aware- ness any conscious method of marking time do not eliminate the influence of physiological or environmental changes. Discussing this, James indicated that the numbers and types of changes, that is the stimulus duration content, dictate the perception.46 gpp_Concept pf_ppipy, Boring47 suggests that because some physiological events must take place before the report- ing of duration, it cannot be an instantaneous experience. He maintains that there can be no immediate experience of duration but that there must be a continuity of duration. This brings up the point as to how much time must pass before it can be said that one event has ended and an- other has begun. Sturt48 notes that there seems to be an 45Fraisse, pp, cit., pp. 15-17. 46James, pp, cit., p. 620. 47Edwin G. Boring, "Temporal Perception and Opera- tionism," American JOurnal p§_§sychology, XLVII (July, 1936), p. 521. 48Sturt, pp, cit., p. 17. ‘flT— ‘ It: intuitiv says tha five sec. longer t] becomes 1 T‘r seconds, Woodrow,5 time over as Presen maximal a: KawalskiSQ [mist eldpg of the "pg summarizin that there \ 20 intuitive duration that man can grasp as a whole. Fraisse49 says that the limit of a perceived present is approximately five seconds. He suggests that an event that lasts for longer than five seconds ceases to be a singular unit but becomes the first of a series of events. The gpacious present may be anywhere from 3.6 to 12 seconds, according to research discussed by James.50 W’oodrow,51 referring to a temppral pppp,p§_attention, that time over which stimuli may be spread and still be perceived as present, suggests, rather than specifies, that there are maximal and minimal durations for this temporal span. Kawalski52 notes from research that a minimum of 1.5 seconds must elapse while W’oodrow53 believes that the maximum limit of the "psychological present" is about six seconds. After summarizing several investigations, however, he concludes that there is a range of unity which probably lies between 49Fraisse, pp, pip,, pp. 84-93. 50James, pp. p_i_t., pp. 612-613. 51WOodrow, "Time Perception," p. 1230. 52Wa1ter Kawalski, "The Effect of Delay Upon the Duplication of Short Temporal Intervals," J6urnalp§_§§r perimental gpvchology, XXXIII (September, 1943), p. 239. 53Woodrow, "Time Perception," p. 1230. 2.3 a: noted be the man's in hat Be11,5 21 2.3 and 12.0 seconds. DEVELOPMENT OF THE CONCEPT OF TIME Persons who accept literally the Scriptural record of the origin of man, believe that man was aware of time and its passing from the time of his creation. The record of the Divine creation of man, as presented in Genesis54 concludes with: "and the evening and the morning were the sixth day." According to the Scriptural account, the mark- ing of time was impressed upon the mind as a permanent, irrevocable memorial by the marking of the Sabbath.55 The passing of time and the seasons were also to be noted through natural phenomena.56 These phenomena were to be the manifestations in the sun, moon, and stars. Those who do not accept the Scriptural account of creation as a record of fact, also agree, however, that man's first concern over time was due to his observations in natural phenomena. Primitive man, according to Bell and Bell,57 became aware of time by noting the rhythmical 54Genesis 1:26-31. 556enesis 2:1-3. 55Genesis 1:14-18. 57Bell and Bell, 92, cit., pp. 16-17. ti changes discern: continu: sermanez 'I‘ led to 1 hensicn Prehensj aftEr ar ing 51m: P ”rent Of some PE: and adul Waiting endingfi -a\\“‘ S S! 6C 61 22 changes both in nature and in himself. The next step of discernment was that time could be classified as present, 58 proposed that the beginning of past, and future. Fraisse the notion of time as a vital factor comes from the experi- ence of successions. Some of these are periodic, some are continuous, and some are interwoven renewals and relatively permanent. Sturt59 theorizes that three primitive experiences led to the development of a time concept: (1) the appre- hension of an event as having duration in time; (2) the ap- .prehension that one event has occurred before, or will occur after another; and (3) the experience of two things occur- ing simultaneously. Attention is directed next to studies of the develop- ment of the time concept by children. There appear to be some perceptions of time which are the same for children and adults. Both have the same feeling that time spent waiting is too long and that time spent in effort is never 61 ending.60 As noted by Fraisse, children first grasp a 58Fraisse, pp, cit., p. 1. 59Sturt, pp, cit., p. 1. 6OFraisse, pp, cit., p. 328. 6lIbid., p. 180. concept organize of time. the abi] for the years f: teen yea Goldston I learning Eral.64 after he developm Velopmen \ 6. the Know 153% GI Ti me Sens 23 concept of the rhythms of everyday experience: next, they organize time sequences: then comprehend the adult measures of time. Fraisse believes that specific training improves the ability of children to estimate duration. The ages for the development of time concepts seem to be about four years for the first awareness and about thirteen to four- teen years for it to reach the adult level.62 Smythe and Goldstone63 concur on this. It is of interest to note that with children, the learning of the concept of time goes from specific to gen- eral.64 Yet another influence, as mentioned by Harrison65 after her working with a selected vocabulary, is that the development of language plays an important part in the de- velopment of time perception. 62E. C. Oakden and Mary Sturt, "The Development of the Knowledge of Time in Children," British qurnal pf, Psychology, XXI (April, 1922), pp. 309-336. 63Elizabeth J. Smythe and Sanford Goldstone, "The Time Sense: A Normative, Genetic Study of the Development of Time Perception," Eegceptugl pppflupppp,§killg, VII (March, 1957), pp. 45-59. 64Louise Bates Ames, "The Development of the Sense of Time in the Young Child,” Journal p£_Genetic Psychology, LXVIII (March, 1946). pp. 97-125. 55M. Lucile Harrison, "The Nature and Development of Concepts of Time Among Children,” Elementary School Journal, XXIV (March, 1934). Pp. 507-514. 7 l tr" L r. ‘1‘ the re: Weber': val. a: q Cuces a incremg consta: uli.66 tiOn Of ConClud poral i: 24 PROBLEMS IN THE STUDY OF TIME PERCEPTION In the consideration of psychophysical problems in the research on time perception one encounters these: (1) Weber's Law, (2) time-order error, (3) indifference inter- val, and (4) methods used in judging. Weber's Q31. As a formula Weber's law reads 95.530. is the differential increase in a stimulus that pro- duces a just noticeable difference (j.n.d.): that is, the incremental ratio of the just noticeable difference is a constant (c) over the entire range of suprathreshold stim- uli.66 Fechner attempted to apply the law to the percep- tion of time and secured varying results. Since Nichols67 concluded in 1890 that Weber's Law does not apply to tem- poral intervals, Mencke,68 Small and Campbell,69 and 66Franklin M. Henry, "Discrimination of the Duration of Sound," Journal p; Egperimental Psychology, XXXVIII (De- cember, 1948), pp. 734-743. 67Nichols, pp, cit., p. 112. 68Eugene Oliver Mencke, "Mbnaurel Differential Sensi- tivity for Short Stimulus Duration," Dissertation Abstracts, XXIV (August, 1963), p. 854. 69Arnold M. Small, Jr., and Richard A. Campbell, "Tem- poral Differential Sensitivity for Auditory Stimuli," Ameri- can Journal pg ggvcholoqv. LXXV (September, 1962), p. 404. Weber's Henry 02 his sho: a sligh1 ration \ Weber re levEl of that the CIEelma: tal Circ duratiOn I_ Stated t: fErenCe 1 “~.‘y‘__‘ 7C 71 Time Inte (septembe‘ 72 73I 74C tiOn’u 25 Edgell,7O have agreed with his findings. In 1940, Gilliland7.l seemed to find, conversely, that Weber's law was applicable for durations from 4-27 seconds. Henry observed that the Weber ratio increased sharply with his shortest time of 32 and 47 milliseconds and that it had a slight tendency to decrease somewhat linearly as the du- ration was increased.72 In a later study he noted that the Weber ratio was slightly higher for his lowest intensity level of 20 dB.73 In still another experiment, he noted that the Weber ratio tended to be higher for low frequencies. Creelman reported that only in some very special experimen- tal circumstances did Weber's law hold approximately for duration discrimination.74 Time-order gpppp, Frankenhaeuser has succinctly stated the time-order concept on psychophysics as "the dif- ference between subjective and objective equality induced 70Edge11, pp. cit., p. 171. 71A. R. Gilliland, “Some Factors in Estimating Short Time Intervals," Journal p§_Experimenta1 Psychology, XXVII (September, 1940), p. 255. 72Henry, pp, cit., p. 737. 73Ibid., p. 739. 74Creelman, "Human Discrimination of Auditory Dura- tion," p. 592. by the orde for example the first 5 the second. whereas whe error is p; tive errors As t creased, th: Crea59- Co: Creased' the Need} that the tin Val 0f aPPrc increaSed HE and the errc 0‘3 Seconds . 26 by the order of presentation..." She illustrates: "When, for example, two objectively equal stimuli are compared, the first stimulus in the pair will usually seem less than the second. In this case the time-order error is negative, whereas when the first stimulus is judged the greater, the error is positive." Experimental data show that the nega- tive errors occur much more frequently.75 As the time interval between the two stimuli is in- creased, the size of the negative time-error seems to in- crease. Conversely, when the interstimulus interval is de- creased, the positive time-error tends to decrease.76 Needham77 made an important contribution by noting that the time-order error is small or absent with an inter- val of approximately three seconds. The time-order error increased negatively with intervals between 3-12 seconds and the error is positive with interstimuli intervals of 0-3 seconds. 75Frankenhaeuser, loc. cit. 76George Kruezer, "The Neurological Level of the Factors Underlying Time-Errors," American Journal p§_Ps - chology, LI (January, 1938), p. 18. 77J. Garton Needham, "The Time-Error as a Function of Continued Experimentation," American Journal p£_Psychol- ogy, XLVI (October, 1934), p. 558. _I_: hensive nor unde ifidiffEIW order er, 27 Indifference Interval. Woodrow78 presents a compre- hensive survey of the literature on the indifference inter- val. There are some intervals that are neither overestimated nor underestimated: this intermediate length is called the indifference interval. It is that point where the time- order error is zero. Woodrow79 does not agree with the generally held view that there is a human tendency to overestimate short inter- vals and underestimate longer intervals. He points out that a short interval may be overestimated if it is the second one. Thus, any constant error is due only to the order of presentation. Stevens,80 after finding an indifference interval between .53 and .87 second, pointed out that his subjects tended to add to long intervals and subtract from short in- tervals. His results differ greatly from those secured by other researchers. 78Woodrow, "The Temporal Indifference Interval Deter- mined by the Method of Mean Error," Journal p§_Experimenta1 Psychology, XVII (April, 1934), pp. 167-188. 79Woodrow, "The Reproduction of Temporal Intervals," JOurnal p§_E§perimenta1 Psychology, XIII (December, 1930), 80Lewis T. Stevens, "On the Time Sense," Mind, XI (JU1Y. 1886). Pp. 393-404. I m . "w" "all: '2 "I ,1‘" seconds 0.5 to 0 Subjects we expec Will ten: avenge. deVelopm tam; Conc It methOds V Waodrow84 interVal 81 82 gisgrimin. 83E 84 . Pp, M 28 Even though indifference intervals from .35 to 5.0 seconds have been reported by investigators, intervals of 0.5 to 0.7 second have been observed by the majority.81 In attempting to answer the question as to why re- searchers obtain such different findings, Stott82 postulated that the results depend in part on the experience of the subjects. A judgment of an experience is made against what we expect it to be. We judge against the average. Subjects will tend to underestimate durations that are above the average. This agrees with Fraisse's83 statement that the development of a central tendency is one of the most impor- tant conditions affecting the indifference interval. It is speculated that different psychophysical methods will result in different indifference intervals. Woodrow84 supports this by stating that an indifference interval derived by the method of comparison is different from an indifference interval derived by the method of 81Woodrow, "Time Perception," p. 1226. 82Leland H. Stott, "The Time-Order Errors in the Discrimination of Short Tonal Durations," Journal p£_§§r perimental Ppycholoqy, XVIII (December, 1935), pp. 743-744. 83Fraisse, pp, cit., p. 120-122. 84Woodrow, "The Reproduction of Temporal Intervals," pp. 474-475. Iii their 511 structurc C36‘.’1C€ e: have varj as {Eport jects of and relax. agined mot used to pr given perm resorted t: Practice bf to 510 Per 29 reproduction. Furthermore, he states that there is no single indifference interval valid for all subjects.85 Methods Used ip_Judging. The instructions given their subjects by the researchers have varied from highly structured and minutely detailed to instruction to use any device except a watch. Devices which subjects have used have varied from "just guessed" or "movements of the feet” as reported by Axel,86 to those reportedly used by the sub- jects of Alvard and Searle:87 (l) judged by muscular strain and relaxation, (2) imagined an auditory rhythm, (3) im- agined motor movement, and (4) imagined clicks of the key used to present the tones. Gilliland's88 subjects, when given permission to employ any device they wished to use, resorted to some form of counting. With these subjects, practice by counting reduced the error from 25-30 percent to 5-10 percent. 85Woodrow, "Time Perception," p. 1226. 86Robert Axel, "Estimation of Time," Archives‘pf Psychology, XII (November, 1924), pp. 45-46. 87Edith A. Alvard and Helen E. Searle, "A Study in the Comparison of Time Intervals," American Journal p§_ Psychology, XVIII, No. 2 (April, 1907), pp. 177-182. BBGilliland. op. cit., pp. 243-255. ":3: r11: urn-av— . . Wood] intervals 1: to their fir the other he movements, t In cc found that 5 while listen movements. 591‘ the dur a PSYCHOPH‘: Severe “moi/Ed in 5 any field of USEd mOre the“: ti” the SUbje \ 89W00dr PP. 473-499. 90 Men WOodr XLV (April, 19 glMaCDO- 3O 89'90 experimental subjects. IGPIOdUCing Woodrow's intervals in an automatic manner, without giving attention to their finger movements, made short reproductions. 0n the other hand, when the subjects concentrated on their movements, the reproductions were too long. In contrast to the findings of others, MacDougall91 found that subjects were more accurate in their estimates while listening passively than when attending to motor movements. From this he judged that motor movements hin- der the duration judgments. PSYCHOPHYSICAL METHODS EMPLOYED IN THE STUDY OF TIME Several psychophysical methods of research have been employed in seeking the answers to sense perception. As in any field of investigation, some of the methods have been used more than have others. Method pf_Reproduction. In the method of reproduc— tion the subject is given either a filled or empty interval. 89Woodrow, "The Reproduction of Temporal Intervals," pp. 473-499. 90WOodrow, "Individual Differences in the Reproduc- tion of Temporal Intervals," American Jopgnal pf Psychology, XLV (April, 1933). PP. 271-281. 91MacDougall, pp, cit., pp. 90-91. Following tl which will : duration) 0 stimulus. Spen val, instru time with a that the su ing inordin It i ual smhject V318 are un overestimat Empt two impact ject he re; 31 Following this exposure, he is to perform some function which will reproduce the variable (in this case it is the duration) of a sound or silence identical to that of the stimulus. 92 employing a sharp rap to mark the inter- Spencer, val, instructed the subject to measure the same length of time with a stop watch. His experience with this shows that the subjects may be aware of distractions, thus caus- ing inordinately short or long responses. 93 work that an individ- It is evident from Edgell's ual subject will favor a selected interval. Longer inter- vals are underestimated, and shorter intervals will be overestimated. Empty intervals of 0.2 to 30.0 seconds bounded by two impact sounds were used by'WoOdrow.94 From this pro- ject he reported that there seemed to be no universal ten- dency for underestimation of long, empty intervals nor overestimation of short ones. The subjects seemed to differ 92Lewellyn T. Spencer, "An Experiment in Time Esti- mation Using Different Interpretations," American JOurnal p§_Psychology, XXXII (October, 1921), pp. 557-562. 93sdge11. 22. cit., pp. 154-174. 94WOodrow. “The Reproduction of Temporal Intervals," pp. 473-499. from day to < of attention :cnSLstently variability : little change uli longer t‘r When h tervals from groups Ieprod 0f the Subjec the IOng Ones interval Of 6 between 600 d] negative to a The efi other than the BilgEr, and De 32 from day to day and with change of attitude. It is worthy of attention, however, that shorter intervals were more consistently judged. There was a noticeable increase in variability for durations between 1.5 and 4-6 seconds, and little change in the relative standard deviations for stim- uli longer than six seconds. 95 used the same method, employing in- When Woodrow tervals from 300 to 4000 milliseconds, he had different groups reproduce different intervals. Eighty-four percent of the subjects made reproductions which were too short for the long ones. By extrapolation he secured an indifference interval of 625.3 milliseconds, which is within the range between 600 and 700 milliseconds where the change from a negative to a positive error appeared. The effects of extraneous sounds, that is sounds other than the stimulus, were also investigated by Hirsh, Bilger, and Deatherage.96 They reported that the duration of a reSponse in noise after stimulation in quiet is longer 95Woodrow, "The Temporal Indifference Interval De- termined by the Method of Mean Error," pp. 167-188. 961. J. Hirsh, R. C. Bilger, and B. H. Deatherage, "The Effects of Auditory and Visual Background on Apparent Duration," American Journal p£_gsycholoqy. LXIX (December, 1965). Pp. 561-575. =5 the man \ther 8 33 than the duration of a response in quiet following stimula- tion in noise. The differences in the responses decrease as the noise level is decreased. Still another factor, the time lapse between the end of the stimulus and the beginning of the subject's response, was considered by Kawalski.97 From his results, he con- cluded that the delay interval had no appreciable effect, noting, however, that there was a tendency for greater ac- curacy of estimates with an increase in the delay time. Of importance to this study is the postulation by Fraisse98 that the method of reproduction results in less error than does the method of production, which in turn gives a smaller error than does the method of estimation. Attention should be called to the fact that with the method of estimation, the variability from one subject to another and the variability within one subject are the greatest. Kawalski99 regards the method of reproduction as the best for both accuracy and flexibility. It should come as no surprise that not all experi- menters had findings which agree with Fraisse and Kawalski. 97Kawalski, pp, cit., pp. 329-346. 98Fraisse, pp. cit., pp. 213-214. 99Kawalski, pp, cit., p. 239. - O'- ‘ H: ibcee ‘$ U {3 ()1 F4 :1 ‘1 inves t entity dl‘ll Sis 34 100 was that the method of The conclusion made by Clausen reproduction was not reliable. It seems reasonable that unless all variables are held constant by all researchers for attempts at exact replications, it can hardly be ex- pected that the same data and conclusions will be obtained. The lengths of the stimuli, the lengths of the intervals, the instructions to the subjects, the method of response, and innumerable other variables may alter the results. Method p; Comparison. Many investigators concur that a different entity is being evaluated by the method of comparison than by any other psychOphysical method. Some investigators recognize the possibility that a different entity is being evaluated by each of the two major sub- divisions of the method of comparison which are: (l) the method of limits, and (2) the constant method. Two stimuli, a standard one and a variable one, are presented in pairs in the method of limits. The variable stimuli are set at selected equal-steps either preceding or following the standard stimulus. The task of the sub- ject is to judge whether the two stimuli are equal or if 100John Clausen, "An Evaluation of Experimental Meth- ods of Time Judgment," Journal p; Experimental Psychology, XL (December, 1950), pp. 756-761. “,8 9 S w- v.. - s3.\-¢ (J: {U '1 (I; that as If a dic 35 one is more or less than the other. Most frequently, in the methods of limits, the stan- dard stimulus is presented first in the pairs and the var- iable stimuli are presented serially. Creelman,101 employing the constant method, ascer— tained that the detection of difference became easier as the difference between the two stimuli was made larger. As he kept a constant difference time of 0.1 second, he found that as the standard stimulus is increased, the detection of a difference between the two decreased. During another experiment he observed that increased signal voltage per- mitted better detection of the difference and greater dura- tion of the difference caused poorer difference detection. 102 At Michigan State University, Shaefor studied the perception of duration using three signals: continuous, warbled, and pulsed. She presented them via the method of constant stimuli. Among her findings were these: 1. A duration difference of at least .28 second was needed for detection of difference for warble tones. 101Creelman, "Human Discrimination of Auditory Dura- p. 26. tion," 102Patricia Shaefor, "A Study of the Perception of Duration of Continuous, Warble and Pulsed Signals," (Unpub- lished M. A. Thesis, Department of Speech, Michigan State University, 1963), pp. 32-33. b) L" 36 2. A duration difference of at least .48 second was needed for detection of differences for continuous tones. 3. A duration difference of at least .51 second was needed for detection of difference for pulsed tones. 4. Subjects had greater difficulty in discrimi- nating short tones than in discriminating long tones. 5. The second of the two stimuli tended to be judged as the shorter (a positive time-error). Mencke,103 using 40, 60, 80, and 100 milliseconds, concluded that the magnitude of the difference limen for short auditory durations depends on the frequency and in- tensity of the variable stimulus and on the duration of the reference stimulus. Milburn104 replicated the study with the exception of using durations of 300, 500, and 1000 milliseconds. He suggests that the magnitude of the rela- tive difference limen for pure tone stimuli depends on the duration and sensation of the reference stimuli but does not depend on the frequency. Method pngstimation. The task of the subject with this psychophysical method is to state verbally how long he 103Mencke, loc. cit. 104Braxton Milburn, "Differential Sensitivity to Duration of Monaural Pure-Tone Auditory Stimuli," Dis- pertation Abstracts, XXIV (December, 1963), p. 2578. ll) :hmxs Q ~nfl' Iran-- U £--Jau ‘ r71 5 " n 1“... 1.. r. '"l. (I) ('1‘ :r (D ) '1 m "h m H m n M 37 thinks a stimulus interval (filled or unfilled) has lasted. 105 found in her work with durations of seconds Sturt and minutes that there was much irregularity in accuracy and in the comparative length of the real and apparent time. She observed no significant tendency of the subjects to overestimate or underestimate the time. Furthermore, prac- tice did not improve the ability of the subjects to be more accurate. Method pj_Production. Some researchers believe this is the opposite of the method of estimation, or as Clausen106 refers to it, the method of verbal estimation. In the meth- od of production the researcher states a certain duration of time, and it is the task of the subject to produce the sig- nal. Particular note should be taken that, with this method, overestimation means that the subject allowed lpp§,chrono- logical time to elapse before feeling the stated duration had passed. Sturt also employed this psychophysical method and with it, too, found a definite tendency to overestimate or underestimate the temporal interval. 105Sturt, pp. p_i___t_., pp. 93—94. 106Clausen, loc. cit. . [when I as he C: lished t C'lraCy frCm thi that the (‘1‘ D v the ‘ < by “one. 5.4 H 71 IL: 38 Method pf Fractionation. In creating scales for various sense modalities, researchers have assigned the sub- jects the task of producing a signal that is half the stan- dard signal. Employing this in hearing research, the sub- ject may be asked to judge duration, pitch, or loudness. The scale for pitch is mel, and for loudness the scale is phon. Gregg107 referred to his unit of duration as "temp" as he constructed a half-time scale and arbitrarily estab- lished one second as one temp. He found considerable ac- curacy in subjects' estimates of half time. According to Fraisse108 there is little to be gained from the construction of subjective time scales. He argued that the apparent half of another apparent duration is equal to the true half of the latter. INDIVIDUAL DIFFERENCES Sex Differences. Research tends to indicate that estimations of time intervals are less reliable when made by women than by men. 107Lee W. Gregg, "Fractionation of Temporal Inter- vals," Journal p§_Experimenta1 Psychology, XLIII (November, 1951). pp. 307-312. 108Fraisse,.pp. cit., p. 145. ' 0) W () '1 m Ste H (D U) r? estmia: 39 Yerkes and Urban,109 employing the method of esti- mation, found that both men and women have tendencies to favor estimates ending in 0 and 5 as well as simple frac- tions of a minute, with women having the greater tendency. Yerkes and Urban110 also found that men slightly overestimated the length of a second and women greatly over- estimated it. With intervals from 18 to 108 seconds men generally underestimated slightly, and women greatly over- estimated. These researchers ascertained that estimates made by women were more variable and less accurate. Both Gulliksen111 and MacDougall112 obtained similar results; that is, that women overestimated durations and were less accurate. Males, according to Axel,113 tend to underestimate durations of time between 15 and 30 seconds. Females, on 109Robert M. Yerkes and F. M. Urban, "Time Estimation in Its Relations to Sex, Age, and Physiological Rhythms," Harvard Psychological Studies, II (June, 1906), pp. 405-430. llorbid. 111Harold Gulliksen, "The Influence of Occupation Upon the Perception of Time," Journal p§_Experimental Psy- chology, X (February, 1927), pp. 52-59. 112Robert MacDougall, "Sex Differences in the Sense of Time," Science, XIX (April, 1904), pp. 707-708. 113Axe1, pp. cit., pp. 30—31. lb if) 1°1~EV V; H W J ‘5 b Slow de' 40 the other hand, overestimate these durations. More recent research done by Gilliland, Hofeld, and Eckstrand114 did not secure data to demonstrate this sex difference. Aqe Qiffegences. Fraisse115 discusses two points regarding age differences. One is that there may be a change in biological time with increase in age. There are a number of biological changes that are greater in the young. More work is accomplished by the youth, resulting in time seeming longer. The other point discussed by 116 is that the child perceives present experience Fraisse in terms of the future, or anticipation, whereas the older person gives more attention to the past. Fraisse hypoth- esizes that man attaches the greater importance to the longer portion of his life. He points out that there is a slow development in the ability to estimate time until a child reaches approximately sixteen years of age. He notes, however, that children seem to grasp the idea of duration at a fairly early age if the method of reproduction is em- ployed. Because a child does not have the ability to use 114Gilliland, Hofeld, and Eckstrand, pp, cit., p. 168. 115Fraisse, pp, cit., p. 236. ll6Ibid°, pp. 181-182. aerial t1 . ”C H 'e cep =2- 1 11. ll? 41 actual time measurements in verbal estimates of time, he is more dependent than an adult on what fills the interval. Axel117 noted a marked improvement in the time esti- mation by children between nine and eleven years of age but negligible improvement after age eleven. When he compared boys nine through fourteen with college men, he observed more accuracy and less variability in time estimations by the college men. Counting seems to be an important cue for time esti- mation for children as well as for adults. Gilliland and Humphreys118 noted this in their comparison of adults with fifth grade children. With both the children and the adults the method of reproduction seemed to be best. 119 points out that while youth is Frankenhaeuser filled with numerous events, life seems to become more auto- matic, thus changing the perception of the passing of time. Motivation and Attitude. Sturt120 believes that time estimates depend on attention. The subject becomes oblivi- ous to the passing of time if attention to it is destroyed. 117Axel, pp, cit., pp. 52-66. 118ci11iland and Humphreys, pp, cit., pp. 125-130. 119Frankenhaeuser, pp, cit., pa 117° 1203mm. op. cit., pp. 89-92. Fraisse the paSSJ 42 121 notes that if a subject pays much attention to Fraisse the passing of time, he will likely overestimate its dura- tion. These findings bear out the fact that attention, as much as any factor, influences time perception. In the first of two studies done by Harton,122 he noted that his subjects reported that time seemed shorter when they were doing successful activity. In his second study he had one group work one maze and another group work several mazes. Time seemed shorter for the subjects striv- ing for one goal, that is, completing one task, than it did for those subjects striving to complete several tasks.. Nervousness and excitement shorten time judgments and according to Nichols,123 items which come first in an experimental situation tend to seem shorter. Mead124 ascertained that both a greater rate of prog- ress and greater proximity resulted in lower estimates of 121Fraisse, pp, cit., pp. 146-147. 122John J. Harton, "The Influence of the Degree of Unity of Organization on the Estimation of Time," Journal pf gpppppl_P§ypholoqy, XXI (July, 1939), pp. 25-49, 123Nichols, pp, cit., p. 82. 124Robert D. Mead, "Time Estimates as Effected by Motivational Level, Goal Distance, and Rate of Progress," Journal pj_§§perimental Psychology. LXIII (October, 1959), pp. 275-279. . 2 t;me.1 from be on the If the unaware taken COnCen‘ sub j 8C exPeri in? ma 43 time.125 If a subject is not sufficiently motivated to keep 126 he may concentrate from being distracted, says Fraisse, on the effort involved, thus making time pass more slowly. If the subject is concentrating on the task itself, he is unaware of the passage of time. According to Woodrow,127 there can be two attitudes taken in estimating time: objective attitude--the subject concentrates upon the characteristics of the stimulus: and subjective attitude--the subject concentrates only on the experience of duration. His research pointed out that giv- ing maximal attention to the second of two tones resulted in an overestimation of the duration, whereas giving passive attention to the second tone resulted in an underestimation. Practice Effects. Experimental studies using fihe Spashore Meappppp.p§_Musica1 Talent indicate that improve- ment with practice is often a result of a change in work rather than in perception. Attitude, division of labor, 125Robert D. Mead, "Effects of Motivation and Prog- ress on the Estimation of Longer Time Intervals," Journal p§_Experimenta1 Psychology, LXV (June, 1963), pp. 564-567. 126Fraisse, pp, cit., p. 220. 127Woodrow, "Time Perception," p. 1228. tense .- C ' V t} a. 5.7.1st Drove Crim: % 1 44 tendency to anticipate, laziness, and indifference often influence the work method. Triplett128 used two groups in her research and found that subjects with a "musical" abili- ty varied less in duration estimations than did the "non- musical." This seems to indicate that practice does im- prove the sense of time. Stott129 found that previous experience in comparing durations was an important factor in ascertaining time- order error and indifference interval. The time-order in- difference point for naive listeners was 0.92 second: while for experienced listeners it was between 1.6 and 2.0 seconds. PERCEPTION OF TIME BY HEARING IMPAIRED SUBJECTS A survey of literature for studies done on the per- ception of time by subjects with any type of hearing im- pairment reveals that nothing has been done, ppp_pp, The researcher investigated books and periodicals in speech and hearing, psychoacoustics, psychology, physiology, and neurology. Personal conversations and personal correspon- dence with some leading research scientists in the field 128Triplett. pp. cit” pp. 260-263. 129Leland H. Stott, "Time-Order Errors'in the Dis- crimination of Short Tonal Intervals," JOurnal pf Egperimen- .Eel.£§ychology, XVIII, No. 6 (December, 1935), pp. 741-766. 45 of audiology130: 131. 132, 133. 134 revealed that they, too, know of no research which had been done on time perception by hearing impaired subjects. Articles, which several of them thought might be pertinent, were not related to percep- tion of duration but, rather, dealt with threshold values and differential sensitivity. SUMMARY There are several main categories of the theories of time perception. One of these holds that within the central nervous system, memory traces or brain traces are established which are later used for comparison between two stimuli. 130Letter from Ira J. Hirsh, Director of Research, Central Institute for the Deaf, St. Louis, Missouri, March 1, 1966. 131Letter from T. Dean Clack, Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, March 7, 1966. 132Letter from James Jerger, Director of Research, Houston Speech and Hearing Center Research Institute, Houston, Texas, March 2, 1966. 133Letter from Merle Lawrence, Director of Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, March 3, 1966. 134Letter from Howard B. Ruhm, Director of Audio- logical Research, The University of Oklahoma Medical Center, Oklahoma City, Oklahoma, March 10, 1966. 46 Another theory states that within the body and phys- iological mechanisms there are cue devices used in time per- ception. A number of researchers believe that time is per- ceived by the amount of change that takes place. Relative to this is the concern that there is a limit to the amount of experience that is considered within one unit-of—organi- zation. Primitive people perceive time by observation of the natural phenomena and by noting bodily changes. Time perception by children is generally on the adult level by the age of 14 years. The development of language plays an important part in this developmental process. In the consideration of Psychophysical problems in the research on time perception, one will encounter weber's Law, time-order error, indifference interval, and methods used in judging. Most research on time perception has employed the psychophysical methods of comparison and re- production, although the methods of estimation and produc- tion have been used extensively. Sex differences, age differences, motivation and attitude, and practice effects, most researchers agree, are important factors in the perception of time. A survey of literature reveals that there has been ‘; ;«r.a-1'rr:"fr" «my: [Tm-“Ll 31 “I 47 no research, per pp, done on the perception of time by per- sons with hearing impairments. CHAPTER III SUBJECTS, INSTRUMENTATION, AND PROCEDURES In the present study the psychometric method of re- production of the stimulus was employed. Guilford135 main- tains that since this allows the judgments to be made by some action on the part of the subject it is the "most natural" psychophysical method. Furthermore, he maintains that a favorable attitude is created in the subject by his being able to control the stimulus. The subjects in this study were to attempt to reproduce the durations of 27 dif- ferent stimuli made up of combinations of the parameters of duration, frequency, and loudness. SUBJECTS Five subjects were selected for this experiment from the clientele of the Speech and Hearing Clinic at Michigan State University. All five of the subjects had binaural sensori-neural hearing impairments, ascertained by pure tone air-conduction and bone-conduction audiometry, with an 135J. P. Guilford, Psychometric Methods (New York: McGraw-Hill Book Company, Inc., 1954), p. 97. 48 I‘. h... (‘1 ._l-. x 4‘ true.“ In. . on. 49 average lOSS of 27 to 33 decibels through the speech range frequencies of 500, 1000, and 2000 cps. The subjects had thresholds in both ears within 5 decibels of each other. The subjects were adults of ages 18, 23, 26, 37 and 43 years with a mean age of 29.4 years. Subjects had been aware of their hearing deficits for at least 10 years. There were two males and three females. The initial con- tact with each subject was made by telephone. The text of WY’I- - .1 -IT-J‘qu.-'W .. 011141 I the experimenters' telephone solicitation for subject par- ° ticipation is given in Appendix C. INSTRUMENTATION Apparatus. The following instruments were used for recording and presentation of the stimuli to the subjects: 1. Low frequency oscillator (Hewlitt-Packard, Mbdel 202-C) 2. Timer (Hunter, Model 100-C, Series D) 3. Tape recorder (Ampex, Model 601-2) 4. Nuxer (Ampex, Model MX-35) 5. Line amplifiers (Ampex, Model 620) 6. Magnetic recording tape (3M, Type 203) 7. Electronic voltmeter (Bruel and Kjaer, Type 2409) 8. Sound level meter (Bruel and Kjaer, Type 2203) 9. Earphones (Telephonics, Model TDH-39) ‘ 10. Aircraft timer stop-computor (Hughes, Model J 9101) 11. 24 volt power supply (Dressen-Barnes, Model 28 2MX) Recording the Stimulus. The stimulus tones for both practice and experimental sessions were generated by the 50 low-frequency oscillator and placed on magnetic recording tape. The signal was timed to within three one-hundredths of the duration desired and sent into line one of the tape recorder. It then passed on to the mixer. At this point the signal was amplified further by the mixer and the line amplifier. Each signal was monitored on the voltmeter. When the programmed stimulus had ended the tone was switched from line one to line two of the recorder. This tone was sent through line two of the mixer, amplified, and also monitored on the voltmeter. The entire recording system had previously been calibrated through the earphones to be used by the subjects during the experimental sessions. Therefore, the reading on the voltmeter represented the level to be heard by the subjects through the earphones. F1 for gure 1 shows a diagram of the recording instrumentation. Selection p_f Stimuli. Three frequencies were chosen presentation to the subjects: 500, 1000, and 2000 cycles per second. These frequencies represent the fre- gu en cy ranges that are critically important for understand- ng human speech.136 They also represent octave steps on 136Hallowell Davis and S. Richard Silverman (eds.), aaring and Deafness (New York: Holt, Rinehart and Winston, 1C0, 1960) . p. 97. ‘. {-nnqja. Una-u” ii 51 the musical frequency scale. PROCEDURES The stimuli were presented at three loudness levels: 60, 70, and 80 phons. Phons are loudness units based on the psychological interpretation of intensity ascertained by having subjects equate the loudness of other frequencies to the loudness of a 1000 cycle tone. Fletcher and Munson137 . Ej established equal loudness contours, using this loudness matching procedure. The various contours were established with the 1000 cycle reference tone set in 10 decibel steps. It was necessary to determine the intensity equiva- lents in decibels (re. .0002 dyne per square centimeter) at which to present the stimuli to the subjects. The research- er employed the intensity levels used by Deal.138 They are presented in Table I. l3'7Harvey Fletcher and W. A. Munson, "Loudness, Its finition, Measurement, and Calculation," Journal Acousti- _]p Society pf America, V (October, 1933), p. 97. 138Deal, pp. cit., p. 106. 52 TABLE I THE AVERAGED INTERPOLATIONS FOR THE INTENSITY EQUIVALENTS OF PHONS GIVEN IN DECIBELS RE 0.0002 DYNE/CM? PHONS FREQUENCIES 6O 7O 80 500 61 70 80 1000 60 70 80 2000 60 70 79 Sounds were presented at three durations: l, 5, and 9 seconds. Because it was important that the results of this experiment measure the subject's reproduction of the duration rather than his reaction time, was set at 1.0 second. the minimum duration Attempting to keep the presentation duration as a "unity of duration," that is, a single event, the maximum duration was set at 9.0 seconds. Woodrow139 ascertained that the upper limit of unity fell somewhere between 2.3 and 12.0 seconds. The stimulus tones were also presented for the 5 acond duration, which is the mid point between land 9 aconds . 139wOodrow, "Time Perception." P- 1230. M; a-J I an __,r-..,z..L:3.—.,--.\.mn l 53 With three frequencies, three loudness levels, and three durations, a total of twenty-seven combinations of stimuli was possible. For example, one combination was: lsecond, 500 cycles per second, 60 phons. ‘I‘en different randomizations (without replacement) were made of these twenty-seven combinations. Each subject heard all ten of the randomizations. Stimuli for presentation during the practice session, prior to the experimental session, were randomized in the same manner using the same table of ran- dom numbers.l4’0 Figure 1 shows a diagram of the instru- mentation employed. Manner _o_f_ Presentation. Each subject was contacted by telephone for an evening appointment hour for the experi- mental session. When he arrived, he was seated and ac- quainted with the part of the apparatus with which he would be concerned. Next, he read the printed instructions on how to respond to the stimuli and was allowed to ask ques- tions about his task and they were answered by the experi- enter. The earphones were adjusted to the subject's ears, 1d the subject was given a practice session using twenty :imuli- Again, the experimenter answered any questions 140Hubert M. Blalock, Jr., Social Statistics (New >rk: McGraw-Hill Book Company, 1960), pp. 437-440. _ -—-_'....~.-WO “I... - '.¢ .ni I .- . ‘. .p": .. _.‘ - 1:315! . '2.-. In. I ._I I. . . u . I . . .J r . 4.. . t . i. 4 is}: a.f1..'ii.l il- u...‘ civil. In! I .msumumco4 wsfipuoowm mo amumMHo xuoam H .ch manage, 4 5 , ~ 83 N 83 , $23.3. _ H 83 H «35 «83488 sz _ summon”? mafia SEE . men: $3. . , 55 asked by the subject. Following the explanation of the procedure and the practice session, the experimental session was begun. The stimulus was presented to the subject; the subject was given 15 seconds in which to make his reproduction of the stimulus duration. The 15 second interstimulus interval was held constant, regardless of the duration of the stimu- lus. Subject Response. After the subject had heard the stimulus, he was to depress a telegraph key for as long as he thought the stimulus had lasted. When the telegraph key was depressed, the subject heard a sound of the same fre- quency and the same loudness heard during the stimulus presentation, to aid the subject in the reproduction of the stimulus duration . The following are the instructions read by the sub- ject prior to the practice session: The task before you is the reproduction of various time intervals. You will hear a series of tones of varied durations, frequencies, and loudness levels. The sound yourwill hear for each stimulus will be continuous. As soon as the tone ceases, you are to depress the tele- graph key which you have before you and hold it down for as long as you think the sound lasted. When the key is depressed you will hear the same pitch and the same loudness that you heard dur- ing the stimulus. This is not a test of your reaction time: --r,-' “W -3 i W“. . . m. ."""."'"“‘"».. ’1?" 'fl. .. I J 1!. 1.. V ... 56 therefore, it is not important that you depress the key with great speed. If you should depress the key too soon you will cut off the stimulus, thus not.hearing all of it. On the other hand, as soon as you are positive the stimulus sound lmas ceased, you are to depress the key. There vwill be adequate time for you to make your re- production of the stimulus duration: but the P.“ longer you wait, the more likely you are to make ‘ 3 errors. You do not have unlimited time to make your reproductions: therefore, if you wait too long before responding you will be cutting off the next stimulus sound. Care should be taken ‘ not to depress the key accidentally. The inter- if vals between stimuli will all be the same. At times you will have a short period of time to wait after making your response: at other times ' you will have a longer period to wait. There will be no alerting signal or tone to indicate when the next stimulus will occur. The onset of the stimulus will be your alerting signal. Try to stay ready throughout the entire test for the onset of the stimulus. You are to be concerned only with the ex- I perience of the duration of the sound. It is important that you make no overt or covert at- tempts to count out the time interval you are reproducing, neither during the stimulus nor during your reproduction of it. Do not count to yourself, look at your watch, make rhythmic motions, be conscious of your respiration, or use any other conscious measuring device. Be- cause this is a test of your ability to repro- duce temporal intervals, not of your ability to count off segments of time, pay attention only to the sensation of the duration. During the practice you will be given twen- ty stimuli. If you have any questions regarding your test, please ask them during or after the practice session. You are to ask no questions during the presentation of the 270 stimuli in the test. The stimuli were presented in ten randomized sched- ules of twenty-seven sounds each. These ten were presented 57 in random order. The subject was given a thirty minute rest break between the presentations of the fifth and sixth schedules. Because, as the experimentation resumed with schedule six, one subject failed to release the tele- graph key until after the second and third stimuli were begun, the experimenter gave her another practice session then proceded with the experiment. The results of measurements with a sound pressure level meter showed that the ambient room noise at the sub— ject's ear level outside the ear cushions was a mean 52.3 dB (re. 0.0002 dyne per square centimeter). Sound pressure readings were taken every ten seconds for three minutes and the mean was calculated. Response _t_.9_ the Stimuli. The taped stimuli were played through channel one of the tape recorder into the mixer and on to the earphones when the subject depressed the telegraph key, channel two of the tape recorder into the mixer permitting the subject to again hear the tone, as it was presented through outputs A and B. The depress- ing of the key also started the timer used to time the duration of the responses. Figure 2 shows a block diagram of the instrumentation for the response. Recording the Response Durations. The timer dial nun-w on“: 1n (upwiwm‘ Wi'K‘F . 1 ... "‘ .. ‘1'. VJ { I n r... a -- _ n g _ -. ' u_ ' ‘c—i 58 . I n I». ..... i... i (15;... .2 H1.LMLP‘L:.: . . .maoammmm Housmawuoaxm can now dowumuauauuumaH mo amuwwfin Moodm N .on was 5.33 r .l \ mmzom _ scams mmzommmam m usduao N Hmnnmso a .D/ 0 $585 mass: m MESH d\ a < usauso amen: H 1.528 59 was read by the experimenter and an assistant. The read- ing was recorded by the assistant while the experimenter reset the timer. CHAPTER IV RESULTS AND DISCUSSION In accordance with the research design presented in Chapter 111, each subject reproduced the 27 combinations of duration, frequency, and loudness. The stimuli were pre- . .AL. .‘C. www.-q_b*w r’.’ . ‘ i ‘fi'i'f . ".. ‘ A. _ r. ‘I ' fl sented in 10 randomized schedules thus resulting in 10 re- sponses to each stimulus combination, or a total of 270 responses by each subject. These responses constituted the raw data of the study. The statistical procedure employed in the analyses of the raw data was as follows: The difference between the actual duration of the stimulus and the duration of the subject's response to that duration was calculated as the difference-time (AT) . Next, this difference-time was divided by the actual duration of the stimulus. This es- tablished a ratio, 91:. During these calculations the sign of the reproduction was retained, i._g., the ratio carried a minus sign if the reproduction was shorter than the stim- ulus duration, or underestimated, and a plus sign if the reproduction was longer than the stimulus duration, or 60 61 overestimated. Employing a ratio permits a difference-time of .10 second to be of greater magnitude when it was in the judgment of a shorter stimulus, such as a l-second stimulus, than it would for a longer stimulus, in this case the 9-sec- ond stimulus. With each subject having reproduced each combination of duration, frequency, and loudness 10 times, the mean of those 10 reproductions was considered as that subject's response to that combination. Therefore, with each subject giving a total of 270 responses, he had a total of 27 aver- aged reproductions. (See Appendix B for the means of the raw data.) The Analysis‘g£_Variance. The data were treated by an analysis of variance. When the analysis of variance is employed, one of the assumptions made is that there is ho- moscedasticity. To ascertain whether or not such an assump- tion can be made with these data, an F-Max test was computed for duration, frequency, and loudness.141 Table 2 contains the results. 141Blalock, 92, cit;, p. 249. rTJWflU-isnrmrm‘Ifl‘F 1'13". . i ‘b‘ . .- r _= m ..___4J' _II _.__.__.F _ 62 TABLE 2 VARIANCES USED TO COMPUTE THE F-MAX TESTS FOR HOMDSCEDASTICITY FOR DURATION, FREQUENCY, AND LOUDNESS DURATION VARIANCE FREQUENCY VARIANCE LOUDNESS VARIANCE ET 1 sec. .086 500 cps .019 60 phons .028 . 5 sec. .004 1000 cps .027 70 phons .020 E 9 sec. .013 2000 cps .020 80 phons .018 a F-Max = 21.5* F-Max = 1.35* F-Max = 1.56* i N-.. L. *2.13 significant at the 1%.level of confidence.142 The results of the F-Max test showed lack of homoge- neity of variance for duration, whereas the variables of frequency and loudness showed homogeneity of variance. With these results in mind, the assumption of homoscedasticity can be made only in part. As Ferguson states, "Tests of normality and homogeneity of variance may be applied: but these tests are not very sensitive for small samples."143'144 Ferguson states further, "When the samples are fairly small, it is usually not possible to rigorously demonstrate lack 1421bid., p. 454. 143George A. Ferguson, Statistical Analysis in Psy- chology and Education (New York: McGraw-Hill Book Company, Inc., 1959), p. 138. 144It seems to be that many researchers consider any sample less than 30 as a small sample. 63 of normality in the data."145 After the testing for homoscedasticity the data were subjected to a 3 x 3 x 3 factorial design analysis of vari- ance with the assistance of the CDC 3600 computer.146 An analysis of variance routine (FACREP, option 3) was em- ployed. Table 3 presents the results of this analysis. TABLE 3 SUMMARY TABLE FOR THE FACTORIAL DESIGN ANALYSIS OF VARIANCE* SOURCE OF SUM OF MEAN SIG. AT VARIANCE SQUARES DF SQUARE F 1%.LEVEL147 DURATION (D) 7.3072 2 3.6536 222.7805 4.61 FREQUENCY(F) .0042 2 .0021 .1280 4.61 D x F .2069 4 .0517 3.1524 3.32 LOUDNESS (L) .0418 2 .0209 1.2744 4.61 D x L .0480 4 .0120 .7317 3.32 F x L .0547 4 .0137 .8354 3.32 D x F x L .2049 8 .0256 1.5610 2.51 ERROR 21.6850 1323 .0164 TOTAL 29.5527 1349 *Individual differences were accounted for in the error term. l45Ferguson,p_p. cit., p. 240. 146D. F. Kiel, A. L. Kenworthy, and W} L. Ruble, Analysis p£_Variance Routines (East Lansing, Michigan: Michigan State University, September 30, 1963), p. 24. 147Ferguson, pp, cit., pp. 310-313. *mfi-mgwnufl'”‘l I . . . a. I _-. I 64 The only significant variable in this analysis was that of duration. There were no significant differences in the subjects' reproductions among the different loudness levels, nor among the different frequencies. The results showed no significant interactions between duration and loudness, frequency and loudness, duration and frequency, or interaction among duration, frequency, and loudness. On the basis of this anlysis, one null hypothesis ' ‘ 111.2 :..'a‘a& SEALS‘IWV“ -) It '. '. .VV. " was rejected: ‘ 1. There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 1 second, 5 seconds, and 9 seconds. On the basis of the same analysis the following null hypotheses were not rejected: 2. There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 500 cps, 1000 cps, and 2000 cps. 3. There is no significant variation in the per- formance of persons with sensori-neural hearing impairments in reproducing temporal intervals of 60 phons, 70 phons, and 80 phons. 4. There is no significant interaction between du- ration and frequency in the performance of per- sons with sensori-neural hearing impairments in reproducing temporal intervals. 5. There is no significant interaction between du- ration and loudness in the performance of per- sons with sensori-neural hearing impairments in reproducing temporal intervals. 65 6. There is no significant interaction between frequency and loudness in the performance of persons with sensori-neural hearing impair- ments in reproducing temporal intervals. 7. There is no significant interaction among duration, frequency, and loudness in the performance of persons with sensori-neural hearing impairments in reproducing temporal f“‘ intervals. 2 Table 4 shows the means and standard deviations of g the reproductions of each stimulus duration in terms of f difference-time. The variables of requency and loudness Efifi were not included because of their having no significant effect. TABLE 4 MEANS AND STANDARD DEVIATIONS OF THE REPRODUCTIONS OF EACH STIMULUS DURATION IN TERMS OF DIFFERENCE-TIME MEAN STANDARD DEVIATION One Second .08290 .16932 Five Seconds -.05483 .09179 Nine Seconds -.08660 .11157 41' On Figure 3, 1?? is plotted as a function of duration showing the means and standard deviations of reproduced temporal intervals. A critical difference test was used to determine where the difference lay among the different yawn. a. uL\ua‘vu'—L 4.111..) ULL’ 1: DML‘UL‘; .40 .30 66 Key: mean i S. D. I". \\ i , \ 5 [j \ 93-. \ .m \ \ l 5 9 DURATION IN SECONDS 3 4. Plotted as a Function of Duration Showing Means and Standard Deviations of Reproduced Temporal Intervals. 67 durations.148 A difference of more than 0.02591 between means would be significant at the 1% level. The results of the critical difference test are found in Table 5. According to this test there are significant differences between all three of the possible pairs of du- ration: l-second and 5-seconds, l-second and 9-seconds, and 5-seconds and 9-seconds. flux". .hwevul.fl“‘ , . . uni; FRI '55! . l ‘ U TABLE 5 CRITICAL DIFFERENCES BETWEEN THE MEANS OF REPRODUCTION TIMES MEANS DIFFERENCES 5 secgnds 9 secondp 1 second .08291 .13774* .16951* -.05483 .03177 5 seconds 9 seconds - -.08660 *Differences between two means significant at the 1%.level. 143K. A. Brownlee, Statistical Theory and Methodology ip_Science and Engineering (New York: JOhn Wiley and Sons, Inc., 1960), p. 252. 68 DISCUSSION Weberflg Law. Through experimentation some research- ersl49'150 have come to the conclusion that Weber's Law does not apply consistently to time. Should it be true that Weber's Law does not hold for judgments of time, the curves presented in Figure 3 would be constant or flat, rather than abruptly changed at the middle frequency. The results of this study seem to indicate that Weber's Law may come closer to being true‘for longer durations than those used in this study. These findings seem to agree, in part, with the re- sults obtained by Gilliland,151 who noted that Weber's Law seemed to hold for durations of 4-27 seconds, and Henry,152 who indicated that such a ratio decreased as the duration increased. The curve for this study is much more flat than the one obtained by Deal153 working with normal hearing 1496i11i1and, pp, cit., p. 255. 150Franklin M. Henry, "Discrimination of the Dura- tion of a Sound," Journal p§_§xpegimenta1 gsychploqy, XXXVIII, No. 6 (December, 1948), pp. 737-739. 151Gi11iland, 10C. cit. 152Henry, loc. cit. 153Deal. 22- Cito', pp. 109, 110. Ear-fr ."fl R rrrr. 7‘31"" ,4 "'1‘". . 3 Ltd.- .;:~‘ . . 69 subjects. In the event of failure of the subject to repro- duce the duration at all, the maximum possible underestima- tion ratio is 1.0. On the other hand, there is no limit to the possibility of the ratio for an overestimation. Effects p§_Fregpency ppg Loudness. A review of the literature reveals that not all researchers have obtained the same results. According to research reported by Fraisse,154 a brief duratiOn filled with sound will seem longer if it is more intense. He added, however, that for longer durations the effects of intensity upon the apparent duration decrease. With a stimulus that varied during its presentation, Wallace and Rabin155 observed that the dura- tion tends to be overestimated if the intensity is increased during the presentation. The results of the present study agree with those results obtained by Deal.156 There is no significant ef- fect by loudness on the perception of duration within the limits used in this study. There were no significant ef- fects by other parameters interacting with the duration 154Fraisse, pp, cit.. pp. 130-134. 155Melvin wallace and Albert I. Rabin, "Temporal Ex— Perience,” Psychological Bulletin, LVII (May, 1960), p. 220. 156Deal, pp. cit., p. 115. 7O variable. As noted by Deal,157 should these parameters be extended, they may indicate different effects. Serial Position. With the stimulus sequences being presented in 10 random orders it was believed that no ef- fect of serial position should be considered. To add to rra the safeguard against effect of serial position each of the subjects was presented the 10 randomizations in dif- ferent orders. The order of which set of 10 randomizations was to be given to each subject was obtained from a table w* of random numbers. _p§ Differences. It was noted in Chapter II that men generally overestimated slightly a stimulus duration, whereas women greatly overestimated it and were less accu- 158 The results of the present study Show that the rate. two men overestimated the l-second duration more than did the three women: the men underestimated the 5-second dura- tion slightly more than did the women: but the women under- estimated the 9-second duration almost twice the amount the men did. Data for this are found in Table 6. Examination of the raw data reveals that, in general, the women 157Deal, pp, cit., p. 115. 158Fraisse, pp, cit., p. 145. 71 overestimated the stimuli more and were less consistent than the men. TABLE 6 MEANS OF SUBJECTS RESPONSES TO STIMULI DURATIONS fIT 1 SUBJECT i I II* III* Iv v i ; Duration I .120 .040 .914 .039 .021 .l3 Duration II -.083 -.057 -.121 -.060 -.054 Duration III -.184 -.059 -.052 -.109 -.030 *Subjects II and III are males Subject Differences. The subjects were asked, as detailed in Chapter III, to use no conscious method of counting or calculating the length of the stimulus duration or the response duration. It was believed that this would help lessen the possibility of subject differences by pre- venting the use of some measuring device a subject may have practiced in the performance of some similar task. All subjects believed, at the end of the experimental session, that they had complied with the request. Several comments were made, such as, "I kept wondering, 'How long would some- one harder of hearing than I estimate the sound to be?'" 72 Regardless of the subjects' comments, their responses were consistent with those found by Woodrow: responses tend to be short when subjects reproduce intervals in an automatic manner.159 All subjects overestimated the l-second duration Fm; from °120 to .020 second, underestimated the 5-second dura- T tion from -.021 to -.083 second, and underestimated the 9-second duration from -.030 to -.184 second. I Effects p§_Duration and Frequency. The finding in this study, that there is no significant effect by interac- tion between duration and frequency, differs from the find- 160 ing by Triplett that a high pitched sound seems longer than does one of low pitch. Cohen, Hansel, and Sylvester,161 found, conversely, that there was a greater inclination for subjects to report higher tones as being shorter. In a study which is somewhat related, Fraisse162 found that when sounds setting off an empty interval are of higher pitch, the interval will appear longer than when limited by sounds 159Woodrow, "Individual Differences in the Repro- duction of Temporal Intervals," pp. 271-281. 160Trip1ett. on. cit., pp. 201-281. 161Cohen, loc. cit. 162Fraisse, pp. cit., p. 130. 73 of lower pitch. Furthermore, he noted that as the differ- ence in pitch of the limiting sounds increases, the longer the interval seems to be. Effects p§_Duration and Loudness. Within the limits of this study there is no significant effect by interaction between duration and frequency. I... r\ .. ”#254,- H‘_* y or “mag-En... Lat-p ..‘o‘ifi'f 1" "\ CHAPTER V SUMMARY AND QONCLUSIONS SUMMARY The study of time and the perception of it has occu- pied the attention of scientists for many years. Both ob- jective and subjective researches have been done on the per- fiq—Anx; . mmzrm : EOE“..—._ I . 1. 1‘ _ 3 ception of time by persons with normal hearing, with some- what contradictory findings. Most researchers do agree, however, that the perception of time is an individual phe- nomenon influenced by numerous factors. The purpose of this study was to investigate the effects of the three parameters - duration, frequency, and loudness - upon the ability of sensori-neural hearing im- paired subjects to reproduce temporal intervals. Even though there has been much study of the effects of the auditory stimulus interval upon the perception of duration, few studies have been concerned with the effects of the interaction of duration, frequency, and loudness. In Spite of lack of agreement by all researchers, there seems to be a general agreement that a high pitched sound 74 75 is perceived longer than a low pitched sound, and that long sound stimuli are less accurately perceived than are shorter sound stimuli. There is apparently no literature on the effects of these parameters on the ability of sensori-neural hearing impaired persons to perceive stimuli durations. Stimuli frequencies of 500, 1000, and 2000 cycles per second were presented at 60, 70, and 80 phon levels for l, 5, and 9 seconds. Twenty-seven different combinations of these parameters recorded on magnetic recording tape were presented to five experimental subjects. Ten different randomized schedules of these combinations were presented to each subject after a 20-stimulus practice session. After the subject heard each stimulus, he depressed a telegraph key for the same length of time he had believed the stimulus to have lasted. During the time the subject depressed the key, he heard a sound of the same frequency and loudness as the stimulus sound he had just heard. This procedure was repeated, within the random schedules, 10 times for each of the 27 stimulus combinations. The ratio, 4%; , was computed by taking the differ- ence-time (the difference between the stimulus duration and the response duration) and dividing it by the actual dura- tion of the stimulus. The ratio carried a minus sign if 76 the reproduction was shorter than the stimulus duration, and it carried a plus Sign if the reproduction was longer. The mean of the subject's 10 reproductions for each of the 27 combinations was considered the subject's score. The F-Max test computation revealed that there was a lack of homogeneity for some of the research parameters. As noted in Chapter IV, however, Ferguson maintains that for a small sample, a lack of homogeneity has a very limited effect upon an analysis of variance.163 The results of the analysis of variance revealed that there was a markedly sig- nificant effect by the duration variable. The effects of the variables of frequency and loudness were minimal or non- existent as was the interaction among duration, frequency, and loudness. Furthermore, there was no significant inter- action among the three parameters. From a critical differ- ence test it was found that Significant differences were present for all frequencies as follows: between durations of l and 5 seconds, 1 and 9 seconds, and 5 and 9 seconds. 163Fergus0n, 92° cit., pp. 138, 240. 7 77 CONCLUSIONS The following conclusions seem to be warranted with- in the limits of this study: l. The reproduction of pure-tone filled temporal Em‘ intervals by sensori-neural hearing impaired subjects ;p_ 3 affected by the duration of the stimulus. Significant dif- L . ferences in time perception exist between the pairs of pure- i; tone stimuli of one and five seconds, one and nine seconds, and five and nine seconds. The five second duration is most accurately reproduced, whereas the one second duration is the most erroneously reproduced. 2. The reproduction of pure-tone filled temporal intervals by sensori-neural hearing impaired subjects pp ppp affected by the loudness of the stimulus presentation. A sound that is slightly above the pure-tone threshold such as 5dB above, is as accurately reproduced as is a sound that is presented well above the threshold, such as 25dB above. 3. The reproduction of pure-tone filled temporal intervals by sensori-neural hearing impaired subjects 1p not affected by the frequency of the stimulus presentation. a 78 4. The interaction among duration, frequency, and loudness has pp_affect upon the reproduction of temporal intervals by sensori-neural hearing impaired subjects. IMPLICATIONS FOR FURTHER RESEARCH Studies of time perception as experienced by persons with sensori-neural or conductive hearing impairments may well include the following: I... " .liu-I- ‘5.-- ”MW . . . ' . p . 1. Extension p£_Paramete;p. Extend the parameters NW] . . ”I employed in this study to include longer and shorter sounds, higher and lower sounds, and louder and softer sounds to determine whether the results obtained in this study will hold for these added stimuli. 2. Changinq the Content pj_the Interval, Select stimuli other than pure tones against a background of silence. Some of the following might be used to fill the duration: narrow-band sound with selected mid-frequencies, filtered speech, competing speech sounds, speech by males and/or females, and speech with background sounds such as street noise or music. The researcher could use empty intervals bounded by any of the sounds noted above. Intermittent presentation or pulsed presentations could be employed while asking the subject to estimate the lapse time or the 79 net time of some part of the duration. 3. Tpp_gpp_p§_9ifferenp Psychophysical Methods. Employ some other psychophysical method of research such as the method of fractionation or the method of paired comparisons for ascertaining the effects of the same para— meters used in this study. 4. Individual pifferencep. Replicate this study on subjects who have sustained their hearing impairments fimn' PT'T’ ’37-‘74“ #1777:— l O "13:.- _ for various lengths of time. Select subjects with unilat- eral hearing impairments to ascertain the possible presence of perceptual differences between the two ears. Note the perception of time by persons with multiple handicaps as contrasted with persons with the same handicaps except with normal hearing. 5. Tgpp_Perception ip Speech ppg Hearing Disorders. Perception of duration may be affected by both neurological and psychological disturbance. Typical of the neurological- ly disturbed is the brain damaged or aphasic, who may suffer both sensori-motor and symbolic difficulties. The estab- lishing of the existence of a difference in time perception by these persons may alter the testing and rehabilitation techniques employed with them. Functional speech disorders such as stuttering may 80 be caused, in part, by distorted time perception. This might be particularly true in cases where the stuttering involves an approach-avoidance conflict. The entire system of interacting time and rhythm may be malfunctioning. There is a possibility that some articulation disorders originate by virtue of distorted vowel perception. Along with this is the fact that delayed speech is frequently caused by improper auditory perception, which in - . . . VTE‘HI’F’TE’VfiiTw I- I _ . #7; . turn may be due to improper time perception. ~ Research on the perception of time as experienced by hearing impaired has just begun. Routine pure tone testing reveals that this population has an altered per- ception of frequency and intensity and their psychological correlates of pitch and loudness respectively. Detailed knowledge of the perception of duration by this population is not yet in hand. An extensive survey of literature reveals that no studies of time perception have been done on either conduc- tive or sensori-neural hearing handicapped subjects. A follow-up study of this one should be done on persons with conductive hearing impairments. This present study could be replicated with subjects sustaining different degrees of hearing impairment. A study could be done on normal 81 hearing subjects and repeated on the same subjects as they sustain experimental hearing losses. The establishing of any difference in time percep- tion by the acoustically handicapped may indicate the need for a change in aural habilitation or rehabilitation pro- no. cedures. It may be found that the sound stimulus for test- ing or rehabilitation should be sustained for a different length of time than iS now believed Optimal. Fm... .V. -. TI .l 3:11.: AS speech reading is considered, it may be found ' that the rate of movement of the articulatory mechanism should be altered to facilitate the learning of speech reading by those who demonstrate a different perception of time. Research could be designed to ascertain the affects of the teaching of speech reading at different rates. In an effort to create a test or series of tests for the perception of time by a hearing handicapped popula- tion, as it would be used in routine speech and hearing therapy, there must be concern over the psychophysical meth- od and the Specific stimulus to be employed. A key consid- eration must be for ease of administration of the test and Simplicity of interpretation of results. Fig.4“.gi“ —.., . . 1 _. £3... ll. L BIBLIOGRAPHY 83 BOOKS Allen, Chalinder. The Tyranny p£_Time, New York: Philo- sophical Library, 1947. Asimov, Isaac. The Clock Wp_Live pp, New York: Ableland- Schuman, 1959. Bartley, S. Howard. Principles p§_Perception, New YOrk: Harper and Brothers, 1958. Bell, Thelma Harrington and Bell, Corydon. The Riddle pf. Time, New YOrk: The Viking Press, 1963. Blalock, Hubert M., Jr. Social Statistics, New YOrk: McGraw—Hill Book Company, 1960. Broadbent, D. E. Perception and Communication, New York: Pergarmon Press, 1958. Brownlee, K. A. Statistical Theory and Methodolpgy'gp Science and Engineering, New York: John Wiley and Sons, Inc., 1960. Cowan, Harrison J. Time and Its Measurement, New YOrk: The World Publishing Company, 1958. Crosby, Elizabeth C., Humphrey, Tryshena and Laver, Edward ‘W. Correlative Anatomy pf the Nervous System, New York: The MacMillan Company, 1962. Davis, Hallowel and Silverman, Richard S. Hearing and Deafness, New York: Holt, Rinehart and Winston, 1964. Deese, James. The Psychology pf Learning, New YOrk-London- Toronto: MCGraw-Hill Book Company, Inc., 1952. De George, D. H. What ;p_Time? London: E. J. Brill, 1949. Dember, William N. The Psychology p§_Perceptiop, New YOrk: Henry Holt and Company, 1960. Dittrich, F. L. and Extermann, R. C. giophysics p§_the Ear, Springfield: Charles C. Thomas, 1963. 84 Eccles, John C. The Physiology p£_Synapses, New York: Academic Press, Inc., 1964. Ferguson, George A. Statistical Analysis ip_Psychology and Education, New York: McGraw-Hill Book Company, Inc., 1959. Fock, V. The Theory p§_§pace, Time and Gravitatiop, New York: MacMillan and Company, 1964. F—M Fletcher, Harvey. §peech and Hearing ;p_Communication, New York: D. Van Nostrand Company, Inc., 1953. Fraisse, Paul. The Psychology p§_Time, Translated by 1 Jennifer Leith, New York: Harper and Row, Publish- f ; ers, 1963. J Frankenhaeuser, Marianne. Estimation p§_Time, Stockholm: Alquist and Wilwell, 1959. Froschels, Emil. Psychological Elements pp Speech, Boston: Expression Company, 1932. Fryer, JUdith. How Wp_Hear, Minneapolis: Medical Books for Children. Gray, Henry. Anatomy p§_the Human Body, Philadelphia: Lea and Febiger, 1942. Guilford, J. P. Psychometric Methods, New YOrk: MCGraw- Hill Book Company, Inc., 1954. Hammerschmidt, William W. Philosophy p§_Time, New York: King's Crown Press, 1947. Hirsh, Ira J. The Measurement p§_Hearing, New York: MCGraw- Hill Book Company, Inc., 1952. Hodgkin, A. L. The Conduction p§_the Nervous Impulse, Springfield: Charles C. Thomas, 1964. Holder, William. Discourse Concerning Time, London: F. Heptinstall, 1894. ‘ fiply Bible, King James Version. 85 James, William. The Principles p§_Psycho10qv. New York: Dever Publications, Inc., 1950. Judson, Lyman S. V., and Weaver, Andrew. Voice Science, New York: Appleton-Century-Crofts, 1965. Kiel, D. F., Kenworthy, A. L., and Ruble, W. L. Analysis p§_Variance Routines, East Lansing, MiChigan: Michigan State University, 1963. Lawson, James L., and Uhlenbeck, George E. Threshold Sig- nals, New York: McGraw-Hill Book Company, Inc., 1950. Lindquist, E. F. Epsiqp and Analysis p; Experiments ;p_Psy- phgloqy and Education, Boston: Houghton-Mifflin Company, 1953. Littler, T. S. The Physics p§_the Ear, New York: The Mac- Millan Company, 1965. Marsden, Dora. The Philosophy pf Time, Oxford: The Holy- well Press Ltd., 1955. Miller, Dayton C. The Science p; Musical Sounds, New York: The MacMillan Company, 1922. Mbnlyn, Adrian C., and Kirkoreau, Yewant H. Structure, Function, and Purpose, New Ybrk: The Liberal Arts Press, 1957. Morgan, Clifford T., and Stellar, Eliot. Psychological Psychology, New York: The MacMillan Company, 1960. Morkovin, Boris. Through the Barriers p£_Deafness_and Isolation, New York: The MacMillan Company, 1960. Mbwrer, Hobart 0. Leapninq Theory and Behaviop, New York- London: John Wiley and Sons, Inc., 1952. Myklebust, Helmer R. The Psychology p£_Deafness, New York: Gruen and Stratton, 1960. Netter, Frank H. Nervous System, New York: Ciba Pharma- ceutical Company, 1962. 86 INewby, Hayes. Audiology, New York: Appleton-Century- Crofts, 1964. Palmer, JOhn, and La Russo, Dominic. Anatomy for Speech and Hearing, New York: Harper and Row, 1965. Pierce, John R., and David, Edward D. Man's World _£ Sound, New York: Doubleday and Company, 1958. ‘3 Pieron, Henri. The Sensations: Their Functions, Processes, and Mechanisms, New Haven: Yale University Press, 1953. Portmann, Michel and Portmann, Claudine. Clinical Audio- metry, Illinois: Charles C. Thomas, 1961. Priestley, J. B. Man and Time, New York: Doubleday Com- pany, Inc., 1964. ‘ 'lu-n‘a)s w'm.‘ inf’mflw'iw Rasmussen, Grant T., and Windle, William F. Neural Mech- anisms p; the Audiotory and Vestibular Systems, Springfield: Charles C. Thomas, 1960. Reitmeister, Louis A. A_Philosophy p; Time, New York: The Citadel Press, 1962. Stevens, S. S. Handbook p: Experimental gpychology, New York: John Wiley and Sons, Inc., 1951. Sturt, Mary. The Psychology pi Time, New YOrk: Harcourt, Brace, and Company, 1925. Truex, Raymond C. Strong and Elwyn's Human Neuroanatomy, Baltimore: The Williams and Witkins Company, 1959. Von Bekesy, Georg. Experiments ;p_Hearing, New YOrk: McGraw-Hill Book Company, Inc., 1960. Von Buddenbrock, Wolfgang. The Senses, Ann Arbor: The University of Michigan Press, 1960° Way, Burnard R., and Green, Noel D. Time and Its Reckoning, New York: Chemical Publishing Company, Inc., 1940. Webstgp's Third New International Dictionary, Springfield, Massachusetts: G. and C. Merriam Company, Publish- ers, 1961. 87 Weber, Ernest Glen, and Lawrence, Mearle. Physiological Acogstics, Princeton-New Jersey: Princeton Univer- sity Press, 1954. ‘Wyburn, G. M., Pickford, R. W., and Hirst, R. J. Human Senses and Perception, Edinburgh and London: Oliver and Boyd, 1964. ‘Wyndham, Lewis. Time and Western Man, Boston: Bacon Press, 1928. E if ARTICLES AND PERIODICALS Alvard, Edith A., and Searle, Helen E. "A Study in the 1 Comparison of Time Intervals," American Journal pp, 1 j Psycholpqv, XVIII, No. 2 (April, 1907). pp. 177-182. .;g Ames, Louise Bates. "The Development of the Sense of Time in the Young Child," Journal p£_Genetic Psychology, LXVIII, No. 1 (March, 1946), pp. 97-125. Angell, F. "Discrimination of Clangs for Different Inter- vals of Time," American Journa1_p§_Psychology, XIII, No. 1 (October, 1900), pp. 58-79. Axel, Robert. "Estimation of Time,” Archives p; Psychology, XII, No. 74 (November, 1924). Boring, Edwin G. "Temporal Perception and Operationism," American Journal pf_Psychplogv. XLVII (July, 1936). Chatterjea, Ron G. "Temporal Duration and Ratio Scale and Category Scale," Journal pg EXperimental Research, LXVII (May, 1964). pp. 412-416. Clausen, JOhn. "An Evaluation of Experimental Methods of Time Judgment," JOurnal p;_Experimenta1 Psychology, XL, No. 6 (December, 1950), pp. 756-761. Cohen, John. "The Experience of Time,“ Acta Psychologica, X (1954)! ppo 207-219. | Cragg, B. G., and Thomas, P. K. "Changes in Nerve Conduc- tion in Experimental Allergic Neuritis," JOurnal p§_ Neurology, Neurosurgery and Psychology, XXVI (1964), pp. 106-115. 88 Creelman, Douglas. "Human Discrimination of Auditory Dura- tion," Joupnal Acoustical Society p§_America, XXIV, Day, R. H. "Perception," Annual RevieW'p£,g§ychology, XV, pp. 1-28. Edgell, Beatrice. "On Time JUdgment," American Journal pg Psychology, LLV, Nos., 3-4 (July-October, 1903), pp. 154-174. .‘ j s 7 Elliott, D. N. "Review of Auditory Research," Anpual 3p: vieW'p§.g§ycholoqy, XV, pp. 57-86. Fletcher, Harvey, and Munson, W. A. "Loudness, Its Defini- tion, Measurement and Calculation," JOurnal Acousti- ppl_Society p£_America, V, No. 2 (October, 1933), . pp. 82-108. Wear-“:7: Henry, Franklin M. "Discrimination of the Duration of a Sound," Journal p§_Experimenta1 Psychology, XXXVIII, No. 6 (December, 1948), pp. 734-743. Gilliland, A. R., Hofeld, Jerry, and Eckstrand, Gordon. "Studies in Time Perception," Psychological Bulletin, LXIII, No. 2 (September, 1943), pp. 162-176. Gilliland, A. R., and Humphreys, Dorothy. "Age, Sex, Method, and Interval as Variables in Time Estimates," Journal p; Genetic Psychology, LXIII, No. 1 (September, 1943), pp. 123-130. Green, David M. "Some Comments and a Correction of Psycho- acoustics and Detection Theory," JOurnal p§,Acousti- cal Society p£_America, XXXIII, (1961), p. 965. Gregg, Lee W; "Fractionation of Temporal Intervals," JOur- nal pf EXperimental Psychology. XLIII, No. 5 (Novem- ber, 1961). Pp. 307-312. Gulliksen, Harold. "The Influence of Occupation Upon the Perception of Time," JOurnal pg Experimental Psychol- ‘ ogy, X (February, 1927), pp. 52-59. 1 Harford, Earl and MuSket, Carolyn. "Binaural Hearing With One Hearing Aid," Journal p£_Speech and Hearing Dis- orders, XXIX, (May, 1964), p. 133. I 89 Harrison, Lucile M. "The Nature and Development of Con- cepts of Time Among Children," Elementary School Journal, XXXIV, No. 7 (March, 1934), pp. 507-514. Harton, John J. "The Influence of the Degree of Unity of Organization on the Estimation of Time," Journal p: General Psychology. XXI (July, 1939), pp. 25-49. Henry, Franklin M. "Discrimination of the Duration of a“ Sound," Journal pf Experimental Psychology. XXXVIII r 5 (December, 1948), pp. 734-743. V i Hirsh, Ira J., Bilger, R. C., and Deatherage, B. H. "The Effect of Auditory and Visual Background on Apparent Duration," American Journal p£_Psychology, LXIX, J. No. 4 (December, 1956), pp. 561-574. EJJ (. Jenkins, Robert A. "Perception of Pitch, Timbre and Loud- ness," Journal p§_the Acogstical Society p£_America, XXXIII (1961), pp. 155-157. Karlin, J. E. "A Factorial Study of Auditory Function," Psychometrika, VII (December, 1942). Kawalski, Walter J. "The Effect of Delay Upon the Duplica- tion of Short Temporal Intervals," Journal ijEgperi- ppntal Psychology, XXXIII, No. 3 (September, 1943), pp. 239-246. Kreezer, George. "The Neurological Level of the Factors Underlying Time-Errors," American Journal pf PS - chology, LI, No. 1 (January, 1938), pp. 18-43. MacDougall, Robert. "Rhythm, Time and Numbers," American Journal p§_Psychology, XIII (January, 1902), p. 88. MacDougall, Robert. "Sex Differences in the Sense of Time," Science, XIX, No. 487 (April, 1904), pp. 707-708. Mallick, A. K. "A Scale for the Measurement of Subjective Duration," Journal pg Psyphologlcal Research, VI . Mead, Robert D. "Effects of Mbtivation and Progress on the Estimation of Longer Time Intervals," Journal 2£_§§f perimental Psychology, LXV (June, 1963), pp. 564-567. 9O . "Time Estimates as Effected by Motivational Level, Goal Distance, and Rate of Progress," Journal p§_Sxperimenta1 Spychology, LXIII (October, 1959), pp. 275-279. Mencke, Eugene Oliver. "Monaural Differential Sensitivity for Short Stimulus Duration," Dissertation Abstracts, XXIV, (August, 1963), p. 854. Milburn, Braxton. "Differential Sensitivity to Duration of Monaural Pure-Tone Auditory Stimuli," Dissertation Abstracts, XXIV, No. 6 (December, 1963), p. 2578. v a. :fi'f‘ififiw 1'7 - O Needham, J. Garton. "The Time-Error as a Function of Con- tinued Experimentation," American Journal p; Psychol- ogy, XLVI (October, 1934), p. 558. Fagin. . YET—9r 1 _' "F i. Nichols, Herbert. "The Psychology of Time," American Jour- nal p§_Psychology, IV, No. 1 (April, 1891), pp. 60- 112. Oakden, E. C., and Sturt, Mary. "The Development of the Knowledge of Time in Children," British JOurnal pg Psychology, XII, No. 4 (April, 1922), pp. 309-336. Pollack, Irwin. "On the Combination of Intensity and Fre- quency Differences in Auditory Discrimination," Jour- ppl_p§_ppp Acoustical Society p; America, XXIII (1961), pp. 1141-1142. Postman, Leo. "Time-Error as a Function of the Method of Experimentation," American Journal p£_Psychology, LX, No. 3 (July, 1944), pp. 421-424. Renshaw, Samuel. "An Experimental Comparison of the Pro- duction and Auditory Discrimination by Absolute Im- pression of a Constant Tempo," Psychological Bulletin. XXIX, No. 9 (November, 1932), p. 659. Schukneckt, H. F., and WOellnew, R. E. "An Experimental and Clinical Study of Deafness From Lesions of the Cochlear Nerve," Journal p£_Larypgology ppg_0tology, LXIX (1955). pp. 75-79. Shore, Irvin and Kramer, Jean C. "A Comparison of Two Pro- cedures for Hearing-Aid Evaluation," Journal p§_ Speech and Hearing Disorders, XXVIII, (May, 1963), pp. 159-170. 91 Small, Arnold M., and Campbell, Richard A. "Temporal Dif- ferential Sensitivity for Auditory Stimuli," American Journal p§_Psychology, LXXV (September, 1962), pp. 401-410. Small, Arnold N., Jr., and Mimified, Fred D. "Effect of Matching Time on Perstimulatory Adaptation," Journal p§_Acoustical Society p£_America, XXIII, (1961). Smythe, Elizabeth J., and Goldstone, Sanford. "The Time Sense: A Normative, Genetic Study of the Develop- . ment of Time Perception," Perceptual_and Motor Skills, F VII, No. 1 (March, 1957), pp. 49-59. Spencer, Lewellyn T. "An Experiment in Time Estimation . Using Different Interpolations," American Journal pg. .=~ gsychology, XXXII, No. 4 (October, 1929), pp. 447- 562. Stevens, Lewis T. "On the Time Sense," Mind, XI, No. 43 (July, 1886). pp. 393-404. Stott, Leland H. "The Time-Order Errors in the Discrimina- tion of Short Tonal Durations," JOurnal p§_Experimen- tal Psychology, LVIII (December, 1935), pp. 743-744. Strunck, Orlo, Jr. "Reliability of Time Estimates," Journal p; SSyChological Studies, XI (1960), pp. 101-103. Triplett, Dorothy. "The Relationship Between the Physical Pattern and the Reproduction of Short Temporal Inter- vals: A Study in the Perception of Filled and Un- filled Time," Psychological Monographs, LXI (1931), pp. 201-265. Wallace, Melvin and Rabin, Albert 1. “Temporal Experience," Psychological Bulletin, LVII (May, 1960), pp. 88-90. Weber, Alden 0. "Estimation of Time," Psychological Bulle- tin, XXX, No. 3 (March, 1933), pp. 223-252. Woodrow, Herbert. "Individual Differences in the Reproduc- tion of Temporal Intervals," American Jou;nal_p§_Ps - chology, XLV, No. 2 (April, 1933), pp. 271-281. 92 . "The Reproduction of Temporal Intervals," Journal pngxperimental Psychology, XIII, No. 6 (December, 1930), pp. 473-499. . "The Temporal Indifference Interval Determined by the Method of Mean Error," Journal p£_Experimenta1 Psychology, XVII, No. 2 (April, 1934), pp. 167-188. Yerkes, Robert M., and Urban, F. M. "Time Estimation in Its Relations to Sex, Age, and Physiological Rhythms," Harvard Psychological Studies, II (June, 1906), pp. 405-430. UNPUBLISHED MATERIALS Creelman, Carleton Douglas. "Human Discrimination of Audi- tory Durations," Unpublished Ph. D. Dissertation, Department of Psychology, University of Michigan, 1960. Deal, Leo V. "The Effects of Duration, Frequency, and Loudness Upon the Reproduction of Temporal Intervals," Unpublished Ph. D. Dissertation, Department of Speech, Michigan State University, 1965. Shaefor, Patricia. "A Study of the Perception of Duration of Continuous, Warble and Pulsed Signals," Unpub- lished M. A. Thesis, Department of Speech, Michigan State University, 1963. W! m mu m. n ”1:450:01ng I I ' . I APPENDIX A s'v’afi-"r 5.7 'fl .r'.‘\-‘tn 94 mH.NI mH.HI NN. cw.HI «o. I no. mm. I an. I. m¢.HI mg. I 0H. ma. mm. I ma. mm.HI No. He. m~.~l ma. I ma. cm. I wo.HI OH mm. I no. I mo. Hm.HI NH. mN.HI Hm. I mm.HI mm. I Ha. ma. I an. «o. mm.HI No. I up. MN.HI Hm. ca. I mm. no. I mm. om.H ma. NE. shunnrtvfusui . om.ml «m. I am. 0H.NI me. am. ma. I ma. do. I on. I mm. NH. I no. MN. mw.HI mN. co. HN.HI Ad. on. mm. I No. m~.HI mm.HI mm. co. oo.~l Nm. NN. Nm.HI RH.MI 5H. no. am. I oo. I mN.~I mN.HI no. 8. 2.7 3.7 oo. 8.? no. I a~.HI am. I no. ca.NI mo. I no. mm.HI «m. I mo. co.HI oo.HI OH. ma. I On. I no. I mm. I «N. I am. 0H.NI ON. I mm. I oo.HI mm. I ma. omH.I we. I qo.HI mm.HI mm. I Nm.NI NH.HI mo. om.NI no. I No. HH.HI «o. I NN.I mm.HI em. I HN. mm. I me. I am. wc.al No. mm.HI mm. I ma. H¢.~I um. I Ho. Nw.HI no. «on om.AI on. I no. recu¢n~¢In~or~cocacarqcu¢n~cun~orx HHHHHHHHHNNNNNNNN HNMQ‘MONQO‘S MmMZDz onHH Homnmbm mmzommmm HOMNNON nz< onHNMDO quanBm H HUNONDN mmzommmm HQNNNDN Qz< ZOHHH EDMONDN 104 ONNO.I ONNH.I OONO.+ ONNO.I NHNH.I OONO.I ONNO.I ONOH.I OONO.+ NNOO.I ONNO.I OOHN.+ «NNO.I NNNO.I OOHO.+ NNNO.I NNNO.I OONO.+ NN«O.I NNNH.I OONO.I NNNO.+ O««H.I OOOO.+ ««OO.I ONNO.I OOHO.+ OH NN«O.I ONNO.I OOOO.I HONO.+ H«NO.+ OOOH.+ NNOO.+ OONO.I OONO.+ NNHO.+ ONOO.I OONH.+ OOOO.+ ONNO.I OONO.+ N««O.I HNNO.I OONO.I NNOO.+ ONHO.+ OONO.+ NNNO.I ONNO.I ONOH.+ ««NO.I OO«H.I OOHO.+ O NNOO.I ONNO.+ NO«O.+ NNOO.I ONNO.I OONN.+ HONO.I ONOO.+ NOHO.+ NNHH.I N«OO.I OONH.+ NN«O.I NOHH.I NONO.I NN«O.I ONOO.+ NO«O.I OOHO.I N«OH.I NO«O.I ««NO.+ ONOO.+ OOOO.+ NNOO.I ONNO.I HONO.I N HO«O.I ONOH.I OONO.I OONO.I OHNO.I ONOH.I NHNO.I OONO.I NOHO.+ NH«O.I ONNO.I NO«O.I NNNO.I O««O.I OOOO.I NNHH.I O«HH.I ONOH.+ NNOO.I ONNH.I NONO.I NNOO.+ ONHO.I OOHH.+ HONO.I ONNO.I OO«O.I ONNO.+ HNNO.I NNNH.I OONO.I H«NO.I OOHH.I N«HO.I NNNH.I NONO.+ NNNO.I ONOO.I ONOH.+ NNNO.+ HNNO.I OONO.+ NN«O.I NNNO.I «ONO.+ ««HO.I NNNO.I OONO.+ ONNO.+ N«NO.I OOHO.I N«NO.+ NONH.I OONO.+ N NHNH.I O«OO.I OONH.+ NNNO.I NNOH.I OOOO.I NNHO.I ONNO.+ OONN.+ ONNH.I ONHN.I OOHO.+ NNNH.I NNNH.I OONH.+ NNNO.I NN«H.I OOOH.I OOOH.I ONOO.+ OONO.+ NNNH.I ONOO.+ OONH.+ NNOH.I ON«H.I OO«O.+ N NNNO.I. O««O.+ OONO.I OOOO.I ONHO.+ ON«O.+ ONHO.I ONHO.I OOHH.I NNHH.+ ONNO.I OONO.I NONO.+ ONNO.I OO«N.+ HHHO.I ONHO.+ OONO.+ N«OO.+ ONNH.+ OONH.I NNNO.I ONNO.I NNNN.+ ««HO.+ ONNO.+ OO«O.I « MMNZSZ ZOHH HUNONDN half}?! 12i— APPENDIX C Good evening. This is Mr. Hartbauer calling from the department of Speech at Michigan State University.. I have been given permission by Dr. Oyer, the director of the Speech and Hearing Clinic, to contact you and requeSt your COOperation on a research project. This would require about three hours of your time some evening next week, at the Speech and Hearing Research Laboratory. You would be paid one dollar an hour for your help. Your task would be simple. It only involves listening to various tones. YOu would be asked to make judgments con- cerning them. Your assistance on this project would be of _ great benefit to us and to persons who are hard of hearing. Is there any certain night, Sunday through Thursday, that would fit best into your schedule? WOuld it be more con- venient for you to come at 6:00 or at 7:00 on that evening? Would you prefer to have transportation'pfOVided fdf"y68? TEXT OF TELEPHONE SOLICITATION FOR SUBJECT PARTICIPATION APPENDIX D CENTRAL INSTITUTE Iron '1‘]!!! DEAF ORAL SCHOOL SCHOOL FOR CHILDREN WITH . HEARING. SPEECH. AND LANCUADI DISORDERS ‘ 5. RICHARD SILVERHAN. PH. Du DIRECTOR 30ARD OF MANAGERS OFFICERS [SIDINT ., A. LONG II PRISIDINTS DRRXN I. WIGHTHAN, JR. IRUHAN WALKER warm 3. anus-In. JI. [ASURBR FRANCIS D. DIVA”, J.- ilS'l’ANT TREASURIR (OBBR‘I' Ii. IHOEND‘RO RRESFONDINO SECRETARY SAMUEL I. EDISON CORDINO SECRETARY JOHN G. BURTON INORARY VICE PRWDIN‘I‘I w. w. BOYD, JR. c. w. GAYLORD HARRY a. xoznnu BOARD MEMBERS IICHARD ll. Aunnno LEWIS 1‘. APPLE ROBERT N. ARTHUR 5. CHARLES BAER ' NGHAM I. BOYD, JI- DAVID R. CALHOUN. JI. FIELDINO CHILDRESS HARRY A. COLLINOIII s. D. CONANT WILLIAM L. DESLOOI ADRIAN rnAzIzn Luca GERDINB IOHN L. CILLIs u. A. GOLDSTEIN JOSEPH H. GRAND ROUERT E. CRDTE JAMES H. GROVE WILLIAM E. GUY JL’STAV L. HARRIS PETER II. HUSCH RICHARD s. JONES HENRY u. KEELER, JI- ALBERT u. XELLII IRVIN 3. LAND WILLARD LEW MORTON J. MAY WALTER a. HAY!“ HENRY N. MC CLUNIY w. BENTON MC HILL”. J. REYNOLDS MEDAI‘I' a. J. HUMMER? LEE I. MIEDRINDHAUU Roman \v. OTTO JANE x. PELTON RICHARD o. RUMIR FRANK R. SHELDON A c. STANNARD L x. srnmouul JOSEPH SUMNER DONALD A. TATIIAN .n C. TAYLon CARL TOLMA): MAHLOM a. WALLACD. Jl GRANT VILLIAuO DAVID I. no)". NORMAN c. hour! New York. 818 SOUTH EUCLID DR. HAX A. COLDITIIH. 'DUHDIR FOR DEAF CHILDREN TEACHERS. COLLEGE RESEARCH LABORATORIES ' SPEECH AND HEARING CLINICS Hum o. LAMS. PM. D.. PRINCIPAL HALLOWILL DAVID. In. 0.. DIRECTOR or flannel: ST. LOUIS. 110., 63110 ‘March 1, 1966 Mr. R. E. Hartbauer, Chairman ' * ~ SPGBCh Department Walla Walla College College Place, Washington 99324 g9. :9 ~° ._“. Dear Mr. Hartbauer: In reply to your letter of 23 February 1966, I must confess that I know of no reference in which the perception of the duration of sounds by hard of hearing persons has been published. The role of frequency or loudness in the perception of auditory duration has not been investigated very thoroughly either but I am sure that you will find appropriate references in the chapter on Time Perception by Woodrow in Handbook of Experimental Psychol (Ed. 8. S. Stevens), 1951, 'Néw‘YOrk, JOhn'Wiley; and also in the new English translation called The Psycholqu_p§ Time by Paul Fraisse, published by Harper andfiRow, Finally, I am enclosing a reprint Of an article that we published some years ago on thgaeffectp _Ot audltglyk as Opposed to visual ambient stimulation on the perception of duration. I hope that the above is of some use. -. 'J;.-,' Sincerély.yours,‘-.- IJH/ezl Ira . Hirsh Encl. Director of Researdh -‘.'.u., on. . \1 THE UNIVERSITY OF MICHIGAN MEDICAL SCHOOL ANN ARIDR KRESGI HEARING REIIAIICH INSTITUTI MERLE LAWRENCI. PH.D.. 0mm I - .' March 7, 1966 Mr. R. B. Hartbauer Chairman ' Speech Department Walla Walla College _ College Place, Washington 99329 Dear Mr. Hartbauer: I Dr. Lawrence referred your question concerning the effects of signal duration among the hearing impaired. A literature search on this topic might begin by locking ..w in the various abstracts under such key words as "temporal integration", "brief-tone audiometry", the "Bunson-Roscoe Law", etc. In addition, here are two articles to get you started: (1) Simon, G. R., The critical Bandwidth Level in Recruiting Bars and its Relation to Temporal Summation, Jour. Auditory Res. 3: 109-119, 1963. This is a dissertation done under Dr. R. Bilger - you might write him for further information. (2) Harris, J.B., et a1., Brief tone audiometry: temporal integration in the hypacusic, Arch. 0tolaryng., 67:699-713, 1958. . . ‘ ' '5.-. Sincerely, .fl. T. Dean Clack ‘TDC:lp i Ila-I 1343 MOURSUND AVENUE. HOUSTON, TEXAS 77025 0 JA4-3136 O TEXAS MEDICAL CENTER JACK L. BANGS. PILD. Executive Director TINA E. BANGS. Ph.D. Associate Director BOARD OF DIRECTORS Oiiicers W D. SUTHERLAND Charrman EmerItus F L. ANDREWS Senior ChaIrman JOS S CULLINAN. ll Chmrman PAT RUTHERFORD. JR. PfeSIdent J CHAS. DICKSON. M.D. First Vice-PreSIdent AIRS. GUS S WORTHAM Second vIce-PreSIdent ROBERT PARKER Seeretary HARRY H. HUDSON Treasurer Members WILLIAM S. BAILEY JAMES A. BAKER. III JOSEPH W. BARBISCH MRS. DAVID BLAND LEE D. CADY. MD. HON. BOB CASEY C C. CODY. III. MD. MRS FRED T. COUPER, JR. CRAIG F. CULLINAN. JR. J A ELKINS. JR. KENNETH FELLOWS MRS. WILBOURN S. GIBBS MISS JEAN GORDON CHARLES W. HAMILTON MRS. DAVID HANNAH. JR. HERBERT H. HARRIS. M.D. MRS C. H. LEWIS E w. MORRIS ROBERT V. NELSON ROSS STEWART JACK T. TROTTER C ",-."" MRS. A. J. WRAY JOSEPH T. AINSWORTH. M.D. 808 R. ALFORD. M.D. MRS. DAVID B. CHALMERS WILLIAM R. CHEEK. M.D. JOE B. CRANE. 0 0.8. WILLIAM S. FIELDS. MD. SANFORD GQUI NONE. PhD. FRANK D. HILL. III. MD. MRS. WILLIAM R. LUMMIS BEN M. NAIL. JR. MD. MRS. SAM ODENSKY ROBERT SCHMITT DON STREETER, PhD. JAMES A. WALSH BEN T. WITHERS. MD Member Agency American Hearing Society 'IIames Jerger, Ph.D Di Director OI Realm, JAMES JERGER. PILD. March 2, l966 R. E. Hartbauer Speech Department Walla Walla College College Place, Washington 9932“ Dear Mr. Hartbauer: The only person that I know of who has considered the problem of duration perception in the hearing-, impaired is Dr. Howard Ruhm. His complete address is: Dr. Howard Ruhm Speech & Hearing Clinic University of Oklahoma Medical Center Oklahoma City, Oklahoma I'm sure that, if you will write directly to him he can put you in touch with the literature you seek. I have taken the liberty of forwarding your letter to him. Sincerely, ’7 (lfich/avL/{,. "'6l«__—— rector of Research - - ° Jere Enc. . cc; Dr. Howard Ruhm Investigating i-iumsn Communication and its Disorders ‘RCHNINSTITLIIFE HRCLC'H" .‘ . _‘-' ‘V.’ - 'I‘TI ‘3‘), WW’ '5,- . ‘1; h THE UNIVERSITY OF MICHIGAN MEDICAL. SCHOOL ANN ARIOI KRESGE HEARING RESEARCH INI‘I'ITU‘I'I MERLE LAWRENCE. PR.D.. 9mm March 3 ’ 1955 Mr. R. E. Hartbauer Chairman Speech Department Walla Walla College Colege Place, Washington 9932” Dear Mr. Hartbauer: Right off hand I have no information on the effects of duration, frequency and loudness on perception of duration of sounds in persons with hearing impairment. However, I am taking the liberty of turning your letter over to Dr. Dean Clack of our Institute, who is familiar with this kind of literature and may be able to help you. Sincerely yours, ‘i;kp74&v(; ‘t§éfi::LLa~c(~ Merle Lawrence ° w - ML:fm EV... ul- . .1 .h‘ M"... ,. 4 Fan-aw.“ 72"? a I— I ’ I . IPIICII AID HIAIINO OINTII THE UNIVERSITY OF OKLAHOMA MEDICAL CENTER 825 wonrnusr sousrsnnrn srsnr oxsanoua our, oxumosursuu March 10, 1966 . 1. -‘_T." R. E. Hartbauer, Chairman Speech Department ' I Walla Walla College - College Place, Washington 99324 Dear Mr. Hartbauer: . ' ‘ . I know of no work concerned with discrimination of acoustic duration in abnormal subjects other than the study done by Dr. William A. COOper under my direction. Dr. C00per's work can be obtained in the form of a doctoral dissertation entitled "The Effect of a Cochlear Pathology on the Difference Limen for Duration", University of Oklahoma, 1964. A less detailed version of Dr. Cooper's experiment is presented along with two foregoing experiments on normal subjects in a manuscript submitted to the Journal of Speech and Hearing Research. This article should be published in the next issue of that Journal. I will send you two reprints as soon as they are available. An excellent review of the “literature in the field of duration discrimination "M 1 f can be found either in Dr. C00per's dissertation or in the dissertations by Dr. Eugene O. Mencke, "Monaural Differential Sensitivity for Short Stimulus Duration", 1963,and Dr. Braxton Milburn, "Differential.Sensitivity to Dura- tion of Monaural Pure-Tone Auditory Stimuli", 1963, both done at the Univer- sity of Oklahoma Medical Center. If I can be of further service to you, please let me know. . - -.\... ’... . .- ',-‘:...‘..‘".." Sincerely, I ‘ I ' Howard Be Ruhm. Phe De HBR:1s Director of Audiological Research APPENDIX E ~ . .L.‘;".u. ._' 3”,? DEPW 0? SPEECH WALLA WALLA COLLEGE COLLEGE PLACE WASHINGTON 99324 9 January 1966 3 Dear Dr. : As part of my Ph. D. program at Michigan ‘~ State University I am writing a dissertation on the effects of duration, frequency, and loudness“ on perception of duration of sounds. To date I have been unable to find any literature on the way in which hearing impaired perceive duration. Dr. Herbert Oyer, my major professor. encouraged my contacting you requesting your directing me to any such research of which you may know. Fur-mum: .. In“. Answer, ..: .V.’ v qr. -. Very sincerely, R. B . Hartbauer Chairman” ‘I . -..a-.. A-’ . -u.‘ e I CI'C