II I i III I III lI’I ‘ III ‘I I I l I Ill TH _ THE EFFECTS OF SELECTED CONTINUOUS AUDITORY DISTRACTIONS ON LIPREADIHG PERFORMAI‘ICE TIncsls for “we Degree of M. A. MICHIGAN STATE UNIVERSITY Ralph Leonard 1962 I} -§ .23 2 3 g; III IIIII II III II IIIII III III III III IIIIII II III III IIIIII 31293 ~nL;‘-.)’..' in," LIB R 4 R Y M1..r_,rI w *3 Sun: I. U! m Vle‘ j] ,3 \- Inna-r. -V ._ \ I‘ll... I. III I 1... luff I I III IIIII-I ABSTRACT THE EFFECTS OF SELECTED CONTINUOUS AUDITORY DISTRACTIONS ON LIPREADING PERFORMANCE by Ralph Leonard The purpose of this study is to analyze the effects of selected continuous auditory stimuli on a single group of trained lipreaders to determine the effects caused by auditory distractors on lipreading performance. Subjects used for this study were twelve graduate and undergraduate students with normal hearing and vision. Silent, motion-picture films were made of a speaker, full—face forward, saying the fifty most frequently spoken words taken from Voelker's study.1 A ten second interval between each word allowed the subjects time to write each word ongnianswer sheet. Four different films were used, each consisted of the same vocabulary, but word order was randomized for each film. Films were produced from the original film. Subjects were trained on a specially pre- pared film until they lipread a minimum of 86 per cent of the vocabulary correctly. Visual, room, and lighting con— ditions were controlled as much as possible. Subjects were subjected to the following continuous auditory 1C. H. Voelker, ”The One Thousand Most Frequent Spoken-Words," Quarterly Journal of Speech, 28 (1942), pp. Ralph Leonard distractors on two successive evenings: (l) quiet (ambient noise level of 55 db), (2) white noise at 80 db, (3) running speech 80 db, (4) background music at 80 db. Each auditory distractor was presented with a different randomized test film. The findings of this study indicated that the selected continuous auditory distractors used, significantly affected lipreading performance. The conclusions which were drawn from this study sug— gest that there is a significant variation among the auditory conditions used, in their effect on lipreading performance. Continuous white noise and running speech effect lipreading performance most significantly. Contin— uous background music effects lipreading performance to a lesser degree than continuous white noise or running speech. Lipreading performance is differentially affected by the Approved by: \ Quirk) 7' Director(:;I (3 auditory distractors. THE EFFECTS OF SELECTED CONTINUOUS AUDITORY DISTRACTIONS ON LIPREADING PERFORMANCE by Ralph Leonard A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF ARTS College of Communication Arts, Department of Speech 1962 TABLE OF CONTENTS Page LIST OF TABLES . . . . . . . . . . . . . . iv LIST OF FIGURES. . . . . . . . . . . . . . v Chapter I. STATEMENT OF THE PROBLEM. I Introduction. . . 1 Statement of Problem and. Purpose of Study . 2 Hypotheses . . . 3 Importance of Study . 4 Definition of Terms . 5 Organization OI the Thesis 6 II. REVIEW OF THE LITERATURE. 7 The Importance of Lipreading . 7 Important Factors of Lipreading 8 The Effect of Noise on Visual Tasks 10 Effects of Noise on Non-Auditory Behavior 11 The Effect of Noise on Intelligence and Psychomotor Performance . . ll Feelings of Annoyance and Fatigue Caused by Noise . 12 Need for Research . 13 III. SUBJECTS, EQUIPMENT, AND TESTING PROCEDURES 14 Subjects 14 Equipment. 14 Procedures 15 IV. RESULTS AND DECISIONS. 22 Results . . . . . . . . . . . . 22 Discussion . . . . . . . . . . . 25 V. SUMMARY AND CONCLUSIONS . . . . . . . . 30 Summary . . . . . . . . . . . . 30 Conclusions . . . . . . 32 Implications for Future Research . . . . 33 ii Chapter APPENDICES. BIBLIOGRAPHY . iii Page 34 A6 Table LIST OF TABLES Wilcoxon Matched-Pairs Signed Ranks Between Conditions . . Comparisons Between both Halves of Lipreading Test Under Each Condition . Percentage of Words Lipread Correctly by Each Subject Under Each Auditory Condition Ranks of Twelve Subjects After Training Under the Four Conditions . . . . . iv Page 24 25 MI “5 LIST OF FIGURES Figure 1. Picture of Speaker 2. Diagram of Physical Arrangement 3. Comparison of the Percentage of Filmed Vocabulary Lipread Correctly by the Subject Group Under Each Auditory Conditions Page 17 18 26 CHAPTER I STATEMENT OF THE PROBLEM Introduction The more complex our civilization becomes the noisier it seems to get. Chapanis, Garner, and Morgan state that the problem of noise has involved the attention of special- ists in many fields. For example, many large cities have developed large campaigns for the reduction of noise; sound- proofing airplanes has been found to eliminate high frequency aircraft noises, this has greatly reduced the annoyance factor of noise for aircraft passengers.l Kryter contends that apparently the most distracting effect that noise has on man's behavior is the masking of speech communication.2 Though the problem of noise has become the concern of more and more people in recent years very few, if any, investi- gations have been attempted concerning visual communication and noise or auditory distraction. Y— 1A. Chapanis, w. Garner, and C. Morgan, Applied Experimental Psychology (New York: John Wiley and Sons, Inc., 1949), pp.PHlA:-hl5. 2 K. D. Kryter, "The Effects of Noise on Man," Journal of Speech and Hearing Disorders, Monograph Supple— ment 1 (1950), p. 83. 2 The ability to receive oral communication is achieved by a combination of sensory modalities. Visual and auditory skills are vital factors in the channel of communication and we know that these two factors are closely related to one another. O'Neill and Oyer point out that the movement and visual shape of a speaker‘s articulators are the important communicative elements for the person with a moderate to severe loss of hearing. When this occurs, the eye becomes the primary receptor and the ear affords some assistance.3 Little is known concerning the distraction or dis— r tortion caused in the communication channel when one sensory modality is working in conflict with the other. Statement of Problem and Purpose of Study The purpose of this study was to investigate and analyze the effects of selected continuous auditory stimuli on a single group of trained lipreaders. From the above investigations and analysis it is hoped that the following questions can be answered: (I) Do auditory dis- tractors affect lipreading performance? (2) If so, which continuous auditory distractors have the greatest effect- on lipreading performance? (3) Is there a sustained incre- ment in lipreading performance caused by auditory distrac- tion or does the trained lipreader eventually adjust to the ¥ 3J. J. O'Neill and H. J. Oyer, Visual Communication for the Hard of Hearing (Englewood Cliffs, New Jersey: ' Prentice-Hall, Inc., 1961), pp. 1. 3 continuous auditory distraction and thus return to his normal level of performance? Hypotheses In order to answer the above questions the following null hypotheses have been proposed: 1. There is no significant variation among all conditions in their effect on lipreading performance. There is no significant difference in lipreading perfor- mance when lipreading in quiet (CO) and lipreading in the presence of white noise (Cl). There.is.no significant difference in lipreading per- formance when lipreading in quiet (co) and lipreading in the presence of speech (C2). There is no significant difference in lipreading per- formance when lipreading in quiet (CO) and lipreading in the presence of music (C3). There is no significant difference in lipreading perfor- mance when lipreading in the presence of white noise (Cl) and lipreading in the presence of speech (C2). There is no significant difference in lipreading per- formance when lipreading in the presence of white noise (Cl) and lipreading in the presence of music (C3). There is no significant difference in lipreading perfor- mance when lipreading in the presence of speech (C2) and lipreading in the presence of music (C3). There is no significant difference between the scores on L; the first and second halves of the lipreading test when taken under the condition of quiet (CO). 9. There is no significant difference between the scores. on the first and second halves of the lipreading test when taken under the condition of white noise (Cl). 10. There is no significant difference between the scores on the first and second halves of the lipreading test when taken under the condition of speech (C2). 11. There is no significant difference between the scores on the first and second halves of the lipreading test when taken under the condition of music (C3). Importance of Study It is quite apparent that rapid recognition and ade— quate concentration are necessary factors in good lipreading performance. O'Neill and Oyer consider three main goals as important in achieving lipreading ability; visual perception, development of attention span, and development of concen- tration.LI The effects of continuous auditory distraction on the individual who utilizes lipreading and residual hearing are of interest to this writer. It is hoped that some understanding of the effect of continuous auditory distraction on the lipreader can be gained in the following manner: (1) training individuals to lipread a certain vocabulary; (2) have the individuals lipread the same .— v—r ,— -———r- 4Ib1d99po 52o 5 vocabulary under certain continuous auditory conditions; (3) statistical analysis of scores achieved by the trained lipreaders under the condition of quiet, and under condi- tions of continuous auditory distraction. Definition of Terms For the purpose of this study, the terms used are defined in the following manner: Normal hearing subjects.--Persons who are able to hear pure tones at 15 decibels, or less, at frequencies of 250 through 8000 cycles per second. Normal vision.-—Persons who possess 20-20 vision or whose vision is corrected to 20—20 vision. Vocabulary.—-The vocabulary words used for this study were taken from "The One Thousand Most Frequent Spoken- Words," by C. H. Voelker.5 The first fifty most frequent- spoken words were employed. These words were presented by one individual on silent film. Continuous auditory distraction.--Sound stimulus carried-out in a continuous fashion with no abrupt change. Continuous auditory distractions used in this study were: (1) 80 db of white noise, (2) 80 db of normal speech, (3) 80 db of background music. Each of the above distractions were continuous for approximately fifteen minutes, when used. 5Charles H. Voelker, "The One Thousand Most Frequent Sgoken—Words," Quarterly Journal of Speech, 28 (1942), pp. 1 9-197. W Organization of the Thesis In this chapter the problem was stated, the importance of the problem discussed, and the hypotheses mentioned. The terms to be used in this study were defined. Chapter II will be devoted to a review of the litera- ture pertaining to the problem. In the remainder of the chapters, the method of the study will be explained, the results presented, and the conclusions drawn. CHAPTER II REVIEW OF THE LITERATURE The Importance of Lipreading Lipreading very often helps the hard of hearing person to communicate. O'Neill and Oyer state that the shape and movement of a speaker's articulators become the important elements to the person with a moderate to severe hearing loss. In this situation lipreading has value as a 1 Watson contends that commun- supplementary communication. ication is much easier for the hard of hearing individual who can coordinate and reinforce what he received from his remaining hearing with clues and information supplied by his eyes.2 Lipreading apparently seems important to the individ- ual who is helped by the hearing aid. Davis points out that many long-time users of hearing aids report that continuous association of hearing and seeing speech is mutually advantageous.3 Newby states that while the lO'Neill and Oyer, op. cit., p. l. 2L. A. Watson, How to Get the Most from Your Remaining Hearing (Minneapolis, Minnesota: The Maico Foundation, 1956), p. 8. 3H. Davis, Hearing and Deafness (New York: Holt, Rinehart and Winston, Inc., 1960), p. 330. 7 8 individual will hear speech more loudly with a hearing aid he may not be able to understand well what he hears. If he can take advantage of the few sounds that he receives aurally and can distinguish the difficult sounds through their appearance on the speaker's mouth, he will communi- cate more effectively. Impprtant Factors of Lipreading It seems quite apparent that much experimental research of lipreading still needs to be done. There is some evidence that certain characteristics of the speaker are important and necessary if adequate lipreading is to take place. Certain effects of speaker characteristics upon lipreading were investigated by Stone. Results showed that normal lip movement, plainly—set expression, and exposure of full torso added to greater success in lip- reading.5 Emphasis of the complexity of the reception of visual speech was stressed by Lowell. Results from Lowell's article suggests the following: (1) Facial expres- sions affect lipreading. For example, an unsmiling face is easier to lipread than a smiling face. (2) Females appear to be more proficient lipreaders than males. (3) Aptitude 4H. A. Newby, Audiology(New York: Appleton—Century~ Crofts, Inc., 1958), p. 129. 5L. Stone, "Facial Cues of Context in Lip Reading," John Tracy Clinic Research Papers, V (1957) cited by J. J. O'Neill and H. J. Oyer, Visual Communication for the Hard of Hearing (Englewood Cliffs, New Jersey: Prentice-Hall, Inc., 1961), p. 48. 9 and personality tests of lipreading are inconclusive as to their relationship to lipreading. (4) The ability to lip- read varies considerably from person to person. This holds true for the normal hearing individual as well as the 6 hearing-impaired person. More experimental research still needs to be done in this area before the above findings can be completely accepted. Distance and speed and their affect upon lipreading was investigated by Mulligan. Upon the viewing of a filmed test of lipreading, subjects results indicated that slower speed of projection resulted in better recognition of filmed materials. The difference in test results when viewing the film at 5, 10, 15, and 20 feet were not significant. How- ever, subjects felt that ten feet seemed to be the most favorable viewing distance.7 O'Neill and Oyer state that little research has been done concerning the environment and its effects on lip— reading.8 They also point out that, Controlled studies should be made of the effects of lighting, physical environment, distractions, and viewing distance upon the lipreading responses of subjects. Research, however, may have been _... 7 _v_ fivfi fir.— ‘7 63. L. Lowell, fNew In-sight into Lipreading," Rehab- ilitation Record, 2:4 (1961), pp. 3-5, quoted in dsh Abstracts, 2 (1962), p. 40. 7M. Mulligan, "Variables in the Reception of Visual Speech from Motion Pictures" (unpublished Master's thesis, Ohio State University, Department of Speech, 1954), cited by O'Neill and Oyer, op. cit., pp. 43-44. 8O'Neill and Oyer, op. cit., p. 43. lO discouraged because of the difficulty of cantrolling the variables existing in such situations. Davis contends that surrounding noises, and other auditory stimuli may affect a person's ability to receive communication in everyday situations.10 Tpe Effectof Noise on Visual Tasks One of the earliest experimental studies concerned with noise and its effect on visual tasks was performed by Luckiesh in 1931. Luckiesh reported that a ”demonstration visual test" was performed six per cent more quickly in the presence of the hum from a motor—generator set.ll More currently, Kryter states that some effects of noise or sound upon certain visual functions, such as flicker, color sensibility, and accommodation and eye movements have attempted to be measured. However, these effects appear to be small and must be measured by extremely accurate methods.12 Broadbent feels that the effects of noise can be com- pared to blinking of the eyes. If the task is one which might be disturbed by blinking, and if each blink is a second or more in length, the task may show effects of noise.13 10 9Ibid., p. 44. Davis, op. cit., p. 330. 11F. K. Berrien, "The Effects of Noise," Psychological Bulletin, 43 (1946), p. 154. 12Kryter, op. cit., p. 20. 13D. E. Broadbent, Perception and Communication (New York: Pergamon Press, 1958), p. 104. 11 Effects of Noise on Non-Auditory Behavior Kryter found, in summarizing laboratory experiments concerned with work output and accuracy that, in general, noise has an adverse initial effect of no great magnitude which rapidly wears off, whether the task be mental or motor. Inconsistent or discontinuous loud mechanical noises and soft gramaphone records of music were more dis- turbing to subjects than continuous loud noises. This indi- cates that disturbance of noise is not just a matter of loudness. There were subjective reports that a sound could be very irritating without lessening the efficiency of performance.l)4 Kryter reports thatnoises having higher frequencies of sound are more annoying than those of predominently low frequencies.15 This factor is also noted by Broadbent.l6 There is a possibility of effects of noise on other tasks. Though little valid research has been done on the effect of noise on memory and attention, Broadbent found that noise did effect a task involving a heavy immediate memory load.17 The Effect of Noise on Intelligence and Psychomotor Performance S. S. Stevens conducted an exhaustive study on the effects of noise. Subjects, in this experiment, were given 14Kryter, op. cit., p. 14. 15Ibid., p. 22. l6Broadbent, op. cit., p. 105. 17Ibid., p. 104. l2 nearly one hundred tests of intelligence and psychomotor efficiency while being exposed to extremely high intensities of airplane noise. The subjects were exposed day after day for as long as eight hours at a time. The subjects involved in this study claimed they did not like this barrage of noise. They also stated they felt fatigued by it and were less tolerant to their friends. However, no significant effects could be detected in any of the test results.18 Studies involving psychomotor performances in noise levels up to 140 db were conducted at Wright Field Air Base in Ohio. Their findings seem to contradict S. S. Stevens findings, however, the Wright Field studies were conducted under less well stabilized and uniform conditions than in Steven's study. At Wright Field investigators found the following results: 1. There was a tendency toward increased time necessary to accomplish a relatively complex psychomotor task. 2. Subjects often forgot or neglected to follow - instructions. 3. There seemed to be an urge to work Egrriedly and get out of the noise situation. Feelings of Annoyance and Fatigue Caused by Noise Kryter notes that unexpected noise can elicit certain startle or fright reactions. Inappropriateness caused by 18Chapanis, t al., op. cit., p. 416. 19An Exploratory Study of the Biolpgical Effects of Noise, Benox Report, Contract N6 ori-320 Tadk Order 44 ONR Fraject NR144079 (Chicago: University of Chicago, 1953), p. 115. 13 noise such as the cracking of peanut shells at a concert, or music when one is trying to concentrate seems to annoy some individuals.20 It was also reported by Kryter that intermittent noise was more annoying than continuous sound.21 Need for Research Review of the literature appears to leave many ques- tions unanswered. Many studies, in the past, seem to have lacked valid experimental conditions and some external variables were not controlled. ”There is still some impor- tant research to be done. We need new methods to study the relation between noise and people. The studies to date have revealed nothing of significance; yet most people are quite emphatic about their dislike of noise."22 Berrien states that under many circumstances it is clear that noise detracts from efficiency and well-being. However, under what circumstances noise is distracting and harmful and for what kinds of people are questions for further research.23 20Kryter, op. cit., p. 17. 21Ibid., p. 18. 22Chapanis, _plgl,, 0p. cit., p. 158. 23Berrien, o . cit., p. 158. CHAPTER III SUBJECTS, EQUIPMENT, AND TESTING PROCEDURES Subjects The subject population consisted of both undergraduate and graduate students enrolled in the Department of Speech at Michigan State University. In all there were twelve sub— jects; three males and nine females. Equipment Hearing screening for the elimination of subjects whose hearing failed to fall within the defined normal limits was done with pure tone audiometer (Beltone Audio- meter, portable model 10C, with Telephonics TDH-39 ear— phones). Vision was checked for the elimination of subjects whose vision failed to fall within the defined normal limits was done with a vision screening device (Snellen E Chart). Running speech and background music was produced on tapes played back on a tape recorder (Wollensak Model T- 1500 tape recorder). A loud speaker (Ampex 620) was used for amplification. White noise generator (Grason-StadlerNoise Generator). l4 15 Sound pressure level meter (MSA Soundscope Model B) was used to determine intensity level for each auditory con- dition, and for the sound pressure level in the experimental room during the condition of quiet. Training lipreading films.--A silent, motion—picture, training film was made specifically for this study. The film consisted of a speaker saying fifty words, filmed head, neck, and full-face forward. Each word on the film was separated by ten seconds of blank film. This ten second interval allowed the subjects viewing the films the time necessary to write the words on answer sheets; 16mm black and white film was used, and was run at the normal speed of 24 frames per second. Movie projector (Bell-Howell 16mm Model #173Iwas used for showing the training and experimental films. Screen (Radiant Screen 4 feet by 4 feet). Procedures Filming.--The vocabulary used for this study consisted of fifty most frequent spoken-words taken from Voelker's study. One individual performed the vocabulary and visual distractions. These were controlled as much as possible by being put on film. Visual distractions were controlled in the following manner: (1) The individual saying the words performed each word from a closed-mouth position. A head- mount was used to control any movements of the head or neck, 16 therefore, only movements of the lips and mouth and eyes were evident in the films. (2) 'Though this was a silent motion-picture film, the individual performed the words with voice during the filming session, this allowed more natural- ness of the individual's delivery of the vocabulary. (3) No number cards were used on the film, as this was consid- ered another possible factor causing visual distraction. (4) The image of the subject was presented for the same length in time for each word. Figure 1 shows how the person was filmed: The film used in this study was put on four different reels, each reel containing the same fifty words but with the words in a different sequence for each reel. The words were respliced from the original film for each fifty word film reel. Therefore, the speaker's movements were controlled throughout the experiment. The word sequence for each film reel was determined by use of a table of random numbers.1 Order of words for each film is illustrated in Appendix A. The room used throughout the training and experimental sessions was a normal classroom, equipped with darkened blinds over the windows. The films were shown in semi~ darkness, this was necessary to allow the subjects to write their responses on the answer sheets. The twelve chairs equipped with writing arms, the projector, screen, and speaker, were arranged as illustrated in Figure 2, 1E. F. Lindquist, Design and Analysis of Experiments in Psychology and Education (Boston: HoughtOn-Mifflin Co., .‘4‘ -“_ ' . ,_. o a} -‘ a... ‘." '-:-- - . , ._--— 1A0 ”— ' _‘7-)..~‘ID*- uv" I ‘ . ‘. ' ‘ 4-v-- . . .rv“ . .l‘ ‘ ‘ ‘v“ '_. _"". (CC-0",“ JC— nil-hour " nay l8 Screen x x x x x x x x Loud ------- speaker “-— x x x x "-Projector x = chairs Figure 2. Diagram of Physical Arrangement The following arrangements Twelve chairs were used, six The first row of chairs were center of the movie screen. from the center of the movie were made for this study: chairs in each row. placed 10 feet from the The second row 15 feet screen. A distance of approximately 2-1/2 feet existed between each chair in the front row. A distance of 3—1/2 feet separated each chair in the second row. The projector was approximately 16 feet from the center of the screen, and the base of the projector was placed on a table 4 feet off the floor. The loud speaker was positioned directly under the projector 16 feet from the center of the movie screen. l9 6. A 2.5 inch lens was used, magnifying the image, on the screen, 1-1/2 times its original size. 7. The lower edge of the movie screen was 3 feet 4 inches off the floor. Testing.—-Each subject was given a practice list of the vocabulary in order to familiarize himself with the words before training began. Copies of the practice list and of the answer sheet used by each subject during the training and experimental sessions are included in Appendix A. The following instructions were given before each showing of the training film until all of the subjects per- formed adequately. After viewing each word on the film you are to write the word on your answer sheet. You will have a ten second interval between each word on the film in which to do this. If you have no idea what the word is be sure and draw a line through the space on the answer sheet, this is important. There was no necessity to repeat the above instruction once the subjects were trained to them. However, at the begin- ning of each experimental evening the instructions were repeated once. All twelve subjects were subjected to the training film of the vocabulary. The subjects were trained at the same time until each one was able to lipread 90 per cent of the vocabulary correctly. At this point, the subjects were con- sidered trained and were ready to begin the experiment. The number of training trials varied taking some subjects only 20 three trials while others had to view the film as many as ten times to accomplish lipreading the film at a 90 per cent correct level. The conditions under which the subjects were trained were the same as the conditions under which the experiment was performed. The only difference was that a new factor was added during the experimental situation. That factor was auditory distraction. The subjects were trained as often as possible at the same time of day that they would be tested in the experiment. The background noise was a sound pressure level of 55 db. This SPL included the noise produced by the projector. Therefore, 55 db. was considered the condition quiet for this study. Subjects were alternated between seats directly in front or in back of their original seat. Seating was staggered for each showing of the film, this controlled a possible learning factor of the film from one position. In this procedure the subjects' scores could not be systematically affected by a distance factor from the movie screen. The experimental procedures were conducted on two evenings one immediately following the other. This was done within a twenty-four hour period so the subjects would not lose their trained efficiency lipreading the vocabulary. Two evenings were also decided upon in an attempt to cut down the fatigue factor that might exist if all conditions were attempted on the same evening. 21 On the first evening of the experiment the training film was again shown in the condition of quiet (55 db). This was considered condition 0 and was the control condition. At the conclusion of the film the answer sheets were collected. Each subject's score on this film determined how well he could lipread the vocabulary under condition 0. This was his final training score. The lowest score was 86 per cent; therefore, all of the subjects lipread a minimum of 86 per cent of the words correctly. After a five minute relaxation period the subjects were shown film #1 under condition #1, which was white noise at 80 db. At the conclusion of the film the subjects' answer sheets were collected. 0n the second evening film #2 was shown under condition #2, which was running speech at 80 db. A tape recording of "Communist Brainwashing Techniques," by Dr. William B. Mayer, was used. After a five minute relaxation period film #3 was shown under condition #3, which was background music at 80 db. A tape recording of "Dim Lights and Blue Music," by Cyril Stapleton and his Orchestra, was used. Condition 1, 2, and 3 were started approximately one minute before the film was shown. This was done to prevent the subjects lipreading performance from being affected by startle response. Thus subjects had about one minute in which to adjust to the auditory conditions before any lipreading took place. Each film was approximately thirteen minutes in length. Each of the auditory conditions lasted approximately fourteen minutes. _CHAPTER 1v RESULTS AND DISCUSSION assess The results were subjected to statistical treatment. The objective of this study was to find out if there were significant differences in the subjects lipreading perfor- mance under the four different conditions. 1. Differences in the four conditions in their effect on lipreading performance.--A test of two-way analysis of variance by ranks was employed to determine if there was any significant difference among four conditions and their effect on the lipreading performance of the twelve trained subjects. The Friedman two-way analysis of variance by ranks, discussed by Siegel,l was used. The formula employed and results were as follows: k 12 Xr2 Nkfi(k+l) 5%; (Rj)2 - 3N (k+l). _ 12 2 2 2 2 _ (12) (a) (4+1) [(21.5) + (21.0) +(29.5) +(48.o) ] (3) (12) (4+1). XP2 = 23.9 lSidney Siegel, Nopparametric Statistics for the Be- havioral Sciences (New York: McGraw-Hill Book Company, Inc. 1956), pp. 166-172. 22 23 The results indicated a Significant variation among the four conditions. 2. Difference between different auditory conditions.—- A test to determine differences between two auditory con- ditions and their effect on lipreading was employed. The four auditory conditions used were compared with each other to determine whether one auditory condition affected- lipreading performance more than another condition. The 2 The Wilcoxon Matched-Pairs Signed-Ranks Test was employed. following comparisons between conditions were analyzed and T_values were determined for each pair. When T_va1ues were referred to a table of critical values of T.in the matched- pairs, the level of significance for the two—tailed test was determined. Auditory Conditions Used 1. Condition 0 . . . . . Quiet (SPL 55 db) 2. Condition 1 . . . . . White Noise (80 db) 3. Condition 2 . . . . . Speech (80 db) 2. Condition 3 . . . . . Music (80 db) 2Ibid., pp. 75—83. 24 TABLE 1 WILCOXON MATCHED-PAIRS SIGNED RANKS ,BETWEEN CONDITIONS l 0.0** 2 0.0** 15.0 3 0.0** 10.0* 11.0 0 l 2 Conditions '7— —v v —v— *Significant at .05 level. **Significant at .01 level. 3. Difference between the two halves of the test for each condition.--A test to determine if there was a signifi— cant difference between the first half and the last half of the lipreading vocabulary test for each condition was attempted. The Wilcoxon Matched-Pairs Signed-Ranks Test was used again. The comparisons between both halves of the lipreading test under each condition were analyzed and T_values were determined. Referral to a table of critical values offI produced the levels of significance for two-tailed tests. The results of this analysis are presented in Table 2. 25 TABLE 2 COMPARISONS BETWEEN BOTH HALVES OF LIPREADING TEST UNDER EACH CONDITION Conditions Condition 0 2.0** Condition 1 l.5** Condition 2 4.5** Condition 3 31.0 '7. 7 . v —v— *Significant difference at .05 level. **Significant difference at .01 level. Discussion The results were obtained by nonparametric statistical tests. Nonparametric statistics were used because the data to be analyzed appeared most suitable for this type of statistical analysis. Null hypothesis were accepted or rejected in the following manner: There is no significant difference among all con- ditions: The Friedman Two-way Analysis of Variance by Ranks was used. This test is useful to indicate whether the size of the scores depends on the conditions under which they were yielded. Siegel notes that this Xr2 test has the I advantage of having tables of exact probabilities for very 3 small samples. 3Ibid., p. 173. lOO ..... 95—. 9o .. T 92.7% 85d 80!! 75~~ 70 +- 654A 603- 52.3% 1. ‘ 55 -I. 59 . 7% 6 0% 50 ~- Per Cent Scores 401— 35" 30-2 25-b 204r 154- 104- O a 1 CO Cl C2 03 Conditions Figure 3. Comparison of the Percentage of Filmed Vocabulary Lipread Correctly by the Subject Group, Under Each Auditory Condition 27 The significance level, calculated by the use of this method, was less than .001, showing a high probability that the auditory conditions did affect the sample population differently. Therefore, rejection of the above null hypothe- sis was indicated. The Wilcoxon Matched-Pairs Signed-Ranks Test was used to determine the differende between pairs of the four con- ditions used, quiet, white noise, music, and running speech. Siegel states that this test is most useful in the following ways: "The researcher can (a) tell which member of a pair is [greater than] which, i.e., tell the sign of the differ- ence between any pair, and (b) rank the difference in order of absolute size."4 The results indicate the following conclusions accord- ing to Table 1: 2. The null hypothesis that there is no significant difference between condition 0 (quiet) and condition #1 (white noise) in their effect upon lipreading performance was rejected. There was a significant difference at a .01 level of probability. 3. The null hypothesis that there is no significant difference between condition 0 (quiet)and condition #2 (running speech) in their effect upon lipreading performance was rejected. There was a significant difference at a .01 level of probability. j“ ‘v' “Ibid., pp. 75-76. 28 4. The null hypothesis that there is no significant difference between condition 0 (quiet) and condition #3 (music) in their effect upon lipreading performance was rejected. There was a significant difference at a .01 level of probability. 5. The null hypothesis that there is no significant difference between condition #1 (white noise) and condition #2 (running speech) in their effect upon lipreading perfor- mance could not be rejected. 6. The null hypothesis that there is no significant difference between condition #1 (white noise) and condition #3 (music) in their effect upon lipreading performance was rejected. There was a Significant difference at the .05 level of probability. 7. The null hypothesis that there is no significant difference between condition #2 (running Speech) and con- dition #3 (music) in their effect upon lipreading perfor— mance could not be rejected. Reference to Table 2 indicate the following results: 8. The null hypothesis that there is no significant difference between the scores of the first and second halves of the lipreading test when taken under the condition of quiet was rejected. Eleven of the twelve subjects lipread as well or better on the first half of the vocabulary under this condition. 9. The null hypothesis that there is no significant difference between the scores on the first and second 29 halves of the lipreading test when taken under the condition of white noise was rejected. Eleven of the twelve subjects lipread better on the first half of the vocabulary under this condition. 10. The null hypothesis that there is no significant difference between the scores on the first and second halves of the lipreading test when taken under the condition of speech was rejected. Eleven of the twelve subjects lip- read better on the second half of the vocabulary under this condition. 11. The null hypothesis that there is no significant difference between the scores on the first and second halves of the lipreading test when taken under the condition of music could not be rejected. CHAPTER V SUMMARY AND CONCLUSIONS Summary Visual as well as auditory skills are important in the communication of hard of hearing individuals. The prob- lems caused by auditory distractions, to the individual who utilizes residual hearing and lipreading, needs thorough investigation. The purpose of this study has been to analyze the effects of selected continuous auditory stimuli on a single group of trained lipreaders to determine the effects caused by auditory distractors on lipreaders performance. The importance of this study centers around the possibility of gaining some understanding of the effects cauSed by certain auditory distractors on the individual who utilizes lipreading and residual hearing. A review of the literature concerning the effects caused by auditory distractors on visual tasks indicates that little research has been accomplished, however, reSearch has been performed concerning noise and its effect on man. There are indications that noise does cause fatigue and inhibits a person's efficiency to perform a task. 30 31 The subjects used for this study were twelve students enrolled in the Department of Speech at Michigan State University. A pure—tone screening test at 15 decibels, for frequencies 250, 500, 1000, 2000, and 4000 cps., and a vision test were employed in selecting subjects for this experiment. Silent, motion-picture films were made of a speaker, full-face forward, Saying the fifty most frequently spoken- words taken from Voelker's study (Appendix A). A ten second interval between each word allowed the subjects time to write each word on the answer sheet. Four different films were used. Each film was produced from the original film, and vocabulary was the same, but word-order was different in each film. Visual distractions were controlled as much as possible. A training program familiarized the twelve subjects to the lipreading situation and trained them to lipread a minimum of 86 per cent of the vocabulary correctly. The training and experimental Sessions were held in the same room and under the same lighting conditions. The subjects were subjected to four continuous auditory conditions on two successive evenings. They lipread the vocabulary under the following auditory conditions: (1) quiet (ambient noise level of 55 db), (2) white noise at 80 db, (3) running speech at 80 db, (4) music at 80 db. Each auditory condition was presented with a different film. The findings of this study indicated that the selected continuous auditory distractors used, significantly affected 32 lipreading performance. The number of correct responses appear to be different on the two halves of the lipreading vocabulary. Conclusions l. The auditory distractors employed in this study significantly affect lipreading per— formance. 2. There is a significant variation among the auditory conditions used in this study in their effect on lipreading performance. a. Continuous white noise and running speech affect lipreading performance most signifi- cantly. b. Background music affects lipreading perfor- mance significantly but to a lesser degree than does continuous white noise and running speech. 3. Lipreading performance is apparently affected differently as evidenced by the fact that: a. Eleven of the twelve subjects lipread the first half of the vocabulary as well or better than the second half under the con— dition of white noise. b. Eleven of the twelve subjects lipread the second half of the vocabulary as well or better than the first half under the con- dition of running speech. 33 c. Subjects lipread both halves of the vocabulary consistently well under the condition of con~ tinuous music. Implications for Future Research Information obtained from this study indicates that the following questions might be suggested for future study: 1. Does continuous white noise cause fatigue in its effect upon lipreading performance? Do lipreaders adjust to distraction when the distractor is continuous running speech? 13 there a differential effect on lipreading performance as a function of intermittent or continuous presentation of an auditory dis- traction? APPENDICES 34 APPENDIX A 35 36 LIST OF FIFTY MOST FREQUENTLY SPOKENvWORDS The following word list was the vocabulary used for this study. "The One Thousand Most Frequent Spoken-Words, Words were taken from: Charles H. Voelker. Journal p£_Speech, 28 (1942), pp. 189-197. the and of a to in it is that have this be work are they do l8. 19. 2o. 21. 22. 23. 24. 25. 26. 27. 28. 29. 3o. 31. 32. 33. 34. for he many you we one an as not if make on there was or all but 35- 36. 37. 38. 39- 40. 41. 42. 43 . 44. 45. 46. 47. 48. 49. 5o . averterly will would with which people more light very at by man these can so his time 37 PRACTICE LIST FORM Lipreading Experiment R. Leonard The following vocabulary will be used in this experi- ment. It will be necessary that you be able to lipread the following list. Please familiarize yourself to this list before me meet. It might help if you practice lip- reading these words in front of a mirror? We will meet in room #235 in the Auditorium. The time: Tuesda , April, 17. Wednesday, April, 18. Frida , April, 20. Tuesday, April, 24. Wednesday, Apr 1, 25.. Time on each of the above days 5:30—6:30 P.M. l. the 26. not 2. and 27. if 3. of 28. make 4. a 29. on 5. to 30. there 6. in 31. was 7. it 32. or 8. is 33. all 9. that 34. but 10. have 35. will 11. this 36. would 12. be 37. with 13. work 38. which 14. I 39. people 15. are 40. more 16. they 41. light 17. do 42. very 18. for 43. at 19. he 44. by 20. many 45. man 21. you 46. these 22. we 47. can 23. one 48. so 24 an 49. his 25: as 50. time I--’ F4 +4 H FJ +4 H r4 )4 H CID-\ImUl-P‘wmI-‘O MI—J OKO 21. 22. 23. 24. 25. 38 ANSWER SHEET FORM NAME 26. 27. 28. 29. 30. 31. 32. 33- KOCIDN O\Ul 4:00 I\) 34. 35- 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. H WCDNONW-twm [C m h) ru m n) +4 H r4 +4 F1 +4 H r4 +4 H U1 .t O) ru H' (D \o a) —4 0x 01 -t U) ro F‘ 53 the and of to in it is that have this be work are they do for he many you we one an as 39 ORIGINAL LIST (Training Film) 26. 27. 28. 30. 31. 32. 33. 31+. 35. 36. 37. 38. 39. 40. 41. 112. 43. at. 1+5. 46. 1.7, 48. 1+9. 50. not if make there was or all but Will would with which people more light very at by man these can so his time 40 WORD ORDER FOR FILM #1 (Shown With White Noise) n) ru n) +0 R) +4 #4 +4 F1 +4 a: +4 FJ +4 F4 fimeOKOCDNIOlw-CI‘WMHO I'D U1 \OCDNOWJYWMH Of 26. would they 27. his be 23. is all 29. but for 30. people not 31. an one 32. these with 33. he was 34. at if 35. more on 36. make this 37. are will 38. there which 39. as I 40. have many 41. or to 42. a it 43. work do 44. man light 45. by can 46. in we 47. that very 48. time the 49. so you 50. and WORD ORDER FOR FILM #2 41 (Shown With Running Speech) will and but of is it the man at time we was would have with his for which you these many there as do 26. 27. 28. 29. 30. 31. 32. 33. 31+. 35. 36. 37. 38. 39. 40. 41. L+2. 1+3. 44. 2+5. 46. 47. 48. 49. SO. by an make are he all more one in not they if or work be so can to people this light very that H \OOJNONUT-P’UUIU }_.+ O I—’ [.4 l2. l3. 14. 15. l6. l7. l8. 19. 20. 21. 22. 23. 24. 25. WORD ORDER FOR FILM #3 was or all but will would with which people more you we one an as not if make on there the and of to 42 (Shown With Music) 26. 27. 28. 30. 31. 32. 33. 311. 35. 36. 37. 3s. 39. 1+0. 1+1. 1+2. 113. 111+. 1+5. 46. 1+7. 1+8. 49. 50. in it is that have light very at by man these can so his time this be work are they do for he many B APPENDIX 43 44 TABLE 3 PERCENTAGE OF WORDS LIPREAD CORRECTLY BY EACH SUBJECT UNDER EACH AUDITORY CONDITION 'Cbnditions I 1' CT 0 i '1 - . + - 2,. - i - 3-- Subjects Quiet White Noise Running Speech Music A 100 64 78 86 B 96 46 56 58 C 86 50 48 50 D 90 62 58 72 E 90 58 64 56 F 86 56 54 66 G 96 68 62. 76 H 90 48 46 46 I 92 68 72 72 J 98 58 6O 62 K 98 88 78 82 L 90 50 56 52 Mean 92.7 59.7 61.0 62.3 45 TABLE 4 RANKS OF TWELVE SUBJECTS AFTER TRAINING UNDER THE FOUR CONDITIONS* , _. ====== Conditions Subject 7'C0 8 Cl C2 03” A 4 l 2 3 B 4 1 2 3 c 4 2.5 1 2-5 D 4 2 1 3 E 4 2 3 1 F 4 2 l 3 G 4 2 l 3 H 4 3 1.5 1.5 I 4 1 2.5 2.5 J 4 l 2 3 K 4 1 2 L 4 l 3 2 Rj 48 0 21.5 21.0 29 5 *1 = Lowest 2 = Next to Lowest 3 = Next to Highest 4 = Highest BIBLIOGRAPHY Books Broadbent, D. E. Perception and Communication. New York: Pergamon Press, 1958. Chapanis, A., Garner, W., and Morgan, C. Applied Experi- mental ngchology. New York: John Wiley and Sons, Inc., 1949. Davis, Hallowell. Hearing apd Deafness. New York: Holt, Rinehart, and Winston, Inc., 1960. Lindquist, E. F. Design and Anal sis of Experiments in Psychology and Education oston: Houghton—MITTlin Company, 1956. Newby, Hayes A. Audiolo . New York: Appleton-Century- Crofts, Inc , 1958. O'Neill, John J. and Oyer, Herbert J. Visual Communication for the Hard of Hearing_. Englewood CIins, New Jersey: Prentice-Hall, Inc., 161 Watson, L. A. How to Getfithe Most from Ypur Remainin Hearing. Minneapolis, Minnesota: The Maico ounda— tion, 1956. Siegel, Sidney. Nonparametric Statistigs for the Behavioral Sciences. New York: McGraW—Hill Book Company, Inc., 1956. Articles and Periodicals Berrien, F. K. "The Effects of Noise," Psychological Bulletin, 43 (1946), 154. DiCarlo, L. and Kataja,R . "An Analysis of the Utley Lip- reading Test," Journal of Speech and Hearing Disorders, 16 (1951), 226- 240. 46 47 Hartmann, G. W. "Changes in Visual Acuity through Simul— taneous Stimulation of Other Sense Organs, Journal of Experimental Psychology, 16 (1933), 393. Kryter, Karl D. "The Effects of Noise on Man," Journal of Speech and Hearing Disorders, Monograph Supplement 1 (19501- ' Laird, D. A. "The Effects of Noise,“ Journal of Acoustical Society of America, 1 (1930), 256. 888 8 ' T Lowell, E. L. "New Insights into Lipreading," Rehabilitation Record, 4 (1961), 3-5. T P ‘ Voelker, Charles H. "The One-Thousand Most Frequent Spoken- Words,” Quarterly Journal of Speech, 28 (1942), 189- 197. ' V W ‘ Reports An Exploratory Study of the Biological Effects of Noise. Benox Report. Contract N6 ori-O2O Tadk 6rder 44 ONR Project NR 144079. Chicago: University of Chicago, 19 53. Unpublished Materials Hast, Malcohm Howard. "The Relative Efficiency of a Stenographer-Typist in Noise and with One-and-Two Channel Listening." Unpublished Master's thesis, Ohio State University, 1958.