Auditory Perceptibility: Acuity and Dominance
- Author:
Edwin B. Twitmyer and Yale Nathanson
An experiment to correlate auditory and visual dominance 1 and bodily laterality 2 led the authors to perfect a method for the determination of gross auditory perceptibility of value to clinicians, generally. It is not demanded of the clinical psychologist that he compete with the aurist, but if a correct diagnosis is to be made he must establish the degree of auditory perceptibility3 and recognize the handicaps of reduced auditory acuity to effect necessary school adjustments and to stress the need for medical care. The use of the ” cricket,” tuning fork, Galton Whistle and the other apparatus usually employed do not give an adequate picture of hearing status. Deafness to the psychologist must be considered in three categories first, total deafness; second, partial deafness in which further involvement is not imminent; and third, progressive deafness. Behavior changes, lack of normal speech development, etc., accompanying deafness are easily observable, and sometimes are the first cue to hearing difficulty. Especially is the problem of hearing crucial in the differential diagnosis of speech defects not only in those lacking speech entirely, but in profound stammering, mutilations, monotone, foreign accent and dialects. Speech, an instinctive urge, displays itself when there is ideational content and an integrated neuro-muscular mechanism capable of producing the necessary performance pattern. It will be observed that deafness is the first possible factor to consider in cases which do not display the speech pattern. For purposes of differential diagnosis the five possible causes of “gross mutilation of speech or total inability to produce articulate sounds necessary for normal speech” 4 are presented herewith:
1 Visual perceptibility: acuity and dominance, by the authors, will appear in The Psychological Clinic. 2 Twitmyer, Edwin B., and Natlianson, Yale, The determination of laterality. Psychol. Clin., 1933, 22, 141-148. 3 Hearing impairment in school children, Penna. Med. J., 1934, 37, 408, resume of work of Dr E. Beatrice Eossell from New York State Journal of Medicine, Dec. 1, 1933.
4-5 Twitmyer, Edwin B., and Nathanson, Yale, Correction of defective speech, 1932, Philadelphia, P. Blakiston’s Son & Co. “1. Deafness. The congenitally deaf child is incapable of acquiring speech in the normal instinctive manner. Determination of this condition is both easy and conclusive Avhere there is tota deafness with an absence of symptoms suggesting some egree o amentia. Where deafness is partial the determination becomes much more difficult. If the condition is caused by some observable structural defect, the aurist can be positive of his diagnosis n cases presenting no observable structural defects he re y on an examination essentially psychological in nature. ie psyc 10 logical data (in these cases consisting of stimulus response behavior patterns and emotional status on the part o e pa len , and conflicting observations of parents) are at times resistant to consistent interpretation. The prognosis for the acquisi ion o speech in cases of deafness is favorable, if the patient be placed m a suitable training environment.
“2. Amentia. The child’s mind and his speech develop pari passu, and if there is a lagging behind in his speec i process, sus picion as to his mental integrity is aroused. The normal child sits erect at six months of age, walks at twelve months, talks m s or sentences at eighteen months. At two years anc nine mon is e has a vocabulary of approximately 640 words, at five years 950 words and at seven years 2900. He acquires first, word symbols for things and actions, then qualities, then proper names. om plete absence of the speech function or a considerable discount at any one of the indicated stages of development siou e viewe as a symptom of general mental deficiency, and in sue i cases a complete psychological examination is indicated.
“3. Brain Injury. Injury of the brain resulting from trauma or infection may interfere with normal speech deveopmen , or occurring after speech has been well established, may rmB a ou a partial or even complete loss of function. In a majority o lese eases the medical history is conclusive. Psychological examination of such cases in most instances reveals the fact that some degree of mental impairment is associated with the speech de ciency. Impairment of speech may also result from cerebral anaemia, or brain fatigue in the form of aphonia or aphasia. “4. Anatomical or Functional Anomalies of the Organs of Speech. These include paralysis of the tongue or facial muscles, malocclusion of the teeth, malposition of the jaw, obstructing tonsils and adenoids, cleft palate, and faulty or inadequate breathing. “5. Negativism. Pathological stubbornness may express itself
in children in the refusal of certain foods, persistence in some unacceptable pattern of behavior despite correction and training, etc. A few cases steadfastly refuse to attempt to make the initial sound in the acquisition of language, and remain mute in consequence. A differential diagnosis of this condition from the mutism, of congenital deafness or profound amentia is not difficidt, being arrived at on the facts of behavior in situations not involving speech.”*
The absolute determination of auditory perceptibility is often difficult.6 Conflicting testimony of parents, attempts to shield the child, lack of knowing or general bias makes their information unreliable. The difficulty is aggravated because of the complexity of the apparatus employed and the necessity to refrain from inadvertent gestures or facial expression. If we permit the child to fix his attention upon a formboard or toy to avoid seeing the instrument used while an assistant stands in back of the child using the cricket or Galton Whistle, it is often difficult to determine whether or not the child is so absorbed in the game or formboard that he does not hear, or whether actual deafness exists. Further, the range of the stimulus is not necessarily within the range of the spoken word. Again, the column of air from the Galton Whistle is sometimes felt by the child, or often he perceives the movement of one’s arm toward the side of his head. From then on, it is most hazardous to guess whether or not he is responding to visual stimulation or if the turning of the head is merely accidental. An attempt to determine bone conduction in the very young child is almost impossible. Clapping the hands, stamping on the floor or in any other way employing impact stimulation has little diagnostic value. With partial deafness or in cases where the child has acquired some speech, the determination of his auditory status is somewhat easier. In these cases we are best guided by the child’s attempt to lip-read and the examiner must be careful to obscure the movement of his lips. The best evidence of hearing deficiency is detected in the monotone and “empty” speech characteristic of the deaf. A partial deafness which does not become progressively worse or a temporary condition which is not too serious may go unchallenged, the afflicted adapting himself by securing a position of vantage, cupping the hand to the ear, focusing attention on the speaker or, what is worse, is an habituation to a process of mentally substituting for omissions. 6 Creak, E. M., A case of partial deafness simulating congenital auditory imperception, J. Neur. Psychopathol., 1932, 13, 133.
The great danger lies in the fact that the onset is gradual and the warning signs thus obscured. Even the physical sign of running ears as sequeke to certain childhood diseases is overlooked. When the onset is gradual, the younger child, unaware of what is occurring, acquires the method of requesting repeated statements. Thus he is dubbed as inattentive, or what is worse, hearing only part of the statement or question attempts an answer without complete understanding. Repeated distress resulting from such procedure causes him to refuse to answer and the best device is to so preoccupy himself with other things that he is obviously not in a position to hear. This carries on for some time until with the approach of adolescence he becomes introverted and finds himself unable to make proper social adjustments. It is rare that the partially deaf individual avails himself of the nine commandments of Berry,7 the first, “Thou shalt frankly confess thy deafness to thyself and before thy fellow men. Let there be no deceit nor false pride.” Unfortunately, the partially deaf individual, even in adolescent life, is not always aware that he or she is suffering from lowered auditory acuity. Great care in the course of examination and keen observation is necessary to make a determination. A case in point is that of a boy, ten years of age, brought to the Clinic 8 for a determination of hearing status. The boy was reported by the parents and teacher to have become totally deaf within the preceding three years. The answers of the child to written questions revealed an inflection and tone of voice not characteristic of the deaf. The child, talked to privately, admitted to the examiner that he was not deaf but that at the age of seven years, being afflicted with a most serious stammer, rather than face the ridicule of his family and schoolmates, he assumed the role of being deaf, which eliminated the necessity for attempting to talk and the subsequent embarrassment. It is conclusive to add that the relief of his stammering likewise effected the “cure” of his hearing. This is in extreme contrast to the case of a twenty-year-old girl, a Senior at this University, whose graduation was being deferred because she had failed to pass her French examinations. A mental examination, supported by her academic record, indicated a good general competency. The girl was asked whether or not she had 7-10 Berry, Gordon, The psychology of progressive deafness, J. Amer. Med. Assoc., 1933, 101, 1599?1603.
8 The Clinic cases herein cited are from the Speech Clinic, Department of Psychology, University of Pennsylvania.
any hearing defect and she very willingly replied that she did not have any defect in her hearing which could be held responsible for the deficiency. However, an audiometric examination indicated that the girl was totally deaf in her left ear. Another illustrative case is that of a girl aged ten years who was being punished and upbraided as a “bad child” because she did not obey ordinary commands. Not only did the parents not realize that the child was considerably deaf, but it seems that the child herself did not appreciate her condition and the further fact that she had become an unusually skillful lip reader which supplemented her hearing. The toss of the head, eye movements, sudden loud speaking or in some instances very quiet speech, the attempt of the individual to place himself in an advantageous position to hear are often the only signs which suggest to the examiner that the child has a hearing difficulty. A recent case of a child suffering from a marked torticolis proved itself the result of trying to raise the “good ear” toward the direction of the sound. Indeed, “The importance of such a cause as deafness in children must take its place somewhere amid problems such as under-nutrition, tuberculosis, postural defects, poor vision, behavior problems, and such.’’9 It is accepted that the deaf child is definitely retarded from one to three years in his school progress, even when diagnostic methods of instruction are employed. The usual methods for determining auditory acuity are unsatisfactory and even audiometric readings are not final criteria unless perceptibility is determined for each ear separately and for both ears together; and with stimuli within the normal range of speech. “Islands of hearing” which change the character of the audiometric report do not necessarily make any contribution to the hearing process for ordinary speech. There is reproduced herewith, a test, T-N-51, developed by the authors in 1931 to determine auditory acuity and ear dominance. The instrument used is an adaptation of existing audiometers, Figure 1.
The sound is produced by a ticking clock in the rear compartment of the audiometer. The sound is conveyed to the subject through the ear pieces connected with rubber tubes, and volume is controlled by a central dial. Each ear can be stimulated separately or both together. ? Macfarlan, Douglas, Salvaging the haid of hearing, Penna. Med. J., 1934. In giving the test the following procedure should be clearly adhered to. First, the ear pieces should be carefully washed in an antiseptic solution and then thoroughly dried. The individual should be comfortably seated on a stool without a back. This facilitates sustained attention. The room should be as nearly sound proof as possible. Place the ear pieces in the subject s ears to demonstrate and accustom him to their presence, then remove them. Take out the clock, show it to the subject and allow him to hear the ticks with the clock held close to the ear to familiarize him with the sound. With the ear pieces removed give the following instructions, demonstrating the procedure where possible. “Hold your fists closely clenched at the level of your chin close to your ears.” (This procedure has a tendency to keep the subject more alert.) “When you hear ticking in your right ear raise your index finger of the right hand; if you hear the ticking in the left ear raise your index finger of the left hand. If you hear ticking in both ears, raise the index finger of each hand. Keep your finger raised as long as the ticking continues. As soon as it stops, lower the finger. As soon as it begins again raise it.” In Audiometer. (Developed from design originally suggested by Joseph M. McCallie, Ph.D., University of Pennsylvania, 1912.) giving the test keep the screen between the audiometer and the subject.
Fill in the data requested at the top of the test sheet and begin. Do not permit subject to watch recording on the test sheets. The Test employed, T-N 51, follows: AUDITORY PERCEPTIBILITY:
ACUITY AND DOMINANCE T-N-51 N ame Age Sex. Occupation Date Exam. Begun” Finished Time Examiner I Right Ear at Zero. Left Ear at Zero . II Right Ear at Zero. (Left Ear Off) III (Right Ear Off) Left Ear at Zero IV Right Ear at Zero. Left Ear at Zero .. Right Ear (Circle highest perceptibility): 0 65 10 55 0 70 15 60 5 75 20 65 10 80 25 70 15 85 30 75 20 90 35 80 25 95 40 85 30 96 45 87 35 97 50 88 40 98 55 89 45 99 60 100 50 AUDITORY PERCEPTIBILITY 227 VI Left Ear (Circle highest perceptibility): 0 65 10 55 0 70 15 60 5 75 20 65 10 80 25 70 15 85 30 75 20 90 35 80 25 95 40 85 30 96 45 87 35 87 50 88 40 98 55 89 45 99 60 100 50 VII Right Ear Highest Perceptibility.. plus 10 reduction to VIII Left Ear Highest Perceptibility. plus 10. reduction to. IX Right Ear A?Highest Perceptibility (Section V) Left Ear B?Highest Perceptibility (Section VI) Both Ears Lower Reading ear reduced by 25. Hearing only in ear at X Has case ever suffered any deafness, ear trouble, or head noises (buzzing or ringing in ears) (Give available information on reverse side) In the opinion of the case which ear is better. No. 1. Right ear and left ear are both given at Zero. Zero on this audiometer means zero amount of interference. In other words, if the dial is turned to 70 degrees it means 70 per cent hearing, the ability to hear when 70 per cent of sound has been shut off. If the subject hears the ticking of the clock in each ear at zero, place a check mark in the space provided. The subject reports whether or not he hears the sound by raising his index fingers, as previously instructed.
No. 2. Without apprising the individual that any change has occurred, allow the right ear stimulation to continue and shut off the sound for the left ear. Sometimes the subject continues to report hearing the sound in the ear from which the sound has been shut off. Repeat this if necessary until it is certain the subject understands. Do not allow any other training periods later. No. 3. In this exercise the right ear stimulation is shut off and the left ear is given at zero.
No. 4. As in test No. 1 both ears are again given at zero. Close watch should be exercised to see whether or not the subject encounters any confusion or whether a decision is difficult at this point for some other reasons.
No. 5. This test is for the right ear only. Sounds to the left ear are completely shut off and the stimulation of the right ear is given as indicated on the test; percentages, 0, 10, 0, 15, 5, 20, 10, 25, etc. When the maximum point of hearing is reached, circle the corresponding number on the test.
No. 6. The procedure employed for test No. 5 is repeated for the left ear, the sounds of the right ear having been shut off. No. 7. Let us assume that the highest perceptibility for the right ear, as indicated by test No. 5, was 80. Write 80 in the space marked “highest perceptibility” , add 10 and then begin reduction from this highest point by 1 degree changes. No. 8. Repeat the procedure of test No. 7 for the left ear. No. 9. In the space indicated, mark “highest perceptibility” , for right ear and in the space indicated, mark “highest perceptibility” , for left ear. Assuming “A” to be 80 and “B” to be 75, in space marked “lower reading” , for both ears write: “left” and following “ear reduced by 25” , write “50.” Then apply stimulation to both ears from this lowest point “50.” Advance dial by 1 per cent until hearing persists only in one ear. Indicate in the space provided which ear and following “ear at” , the percentage of stimulation perceived. No. 10. The information here requested is of importance and any pertinent data should be recorded.
The audiometer reading thus obtained serves two purposes; first, we can make a determination of absolute hearing, and secondly, we can determine ear dominance. Aside from our experimental interest in the question of ear dominance, there has deAUDITORY PERCEPTIBILITY 229 veloped from the 200 eases studied the fact that the perception of sound is not one of mathematical computation; that is to say, 80 per cent in the right ear and 60 per cent in the left ear does not mean either 80 per cent hearing with both ears or the expected “average” 70 per cent perceptibility with both ears, but that the auditory threshold must be experimentally determined. In fact, in some cases in which we find 80 per cent in the right ear and 60 per cent in the left the threshold exceeds the maximum for either ear, 82 per cent, 84 per cent, 85 per cent, etc. This is in keeping with the experiment of the inaudible tuning fork supplementing an audible fork which augments the receptivity of the audible fork. This sum total of cumulative processes we have recognized as sensori-auxilia, the whole being greater than the sum of the parts. The ultimate value, experimentally, of this method for determining auditory dominance is in its inclusion in the battery of tests provided for establishing bodily laterality and eye dominance. However, its greater value perhaps lies in the use for determining general auditory acuity and for calling the attention of the clinical psychologist to the evidences of lessened hearing. Many of the difficulties encountered by the child in school and in social adjustments are referable to hearing defects, and before the complete diagnosis can be written, it is necessary to determine sensorial acuity. Sometimes partial deafness, due to catarrhal conditions, bad dentition, acute inflammatory processes, etc., is only of a temporary nature, in which case well directed observation and a knowledge of the existence of these defects is necessary to prevent what otherwise reflects itself in an unaccountable drop in school work. The human being as a “sound board” is a wellknown concept, and any existing defect reflects itself in a changed behavior. The general psychological examination must take into account sensorial acuity in determining social or educational competency. In vocational adjustment, the importance of such determinations is even more obvious. We must adhere to the basic objectives of human adjustment, to effect greatest usefulness, in terms of units of production, economic stability and human happiness, that situation in which the individual suffers the least number of distressing impinging stimuli. This means that we must place the individual in an environment which draws minimally upon his specific defects and maximally upon those specific abilities which he enjoys the greatest.
From the point of view of general safety and the ordinary social relationships of life, the hard of hearing compete “with the “normals” at a decided disadvantage. The blind live in a relatively protected environment, but the deaf are offered no such protective advantage. Vocational adjustment and whatever hope can be held out to the hard of hearing is ably summed up by Berry:10
“Vocational Measures. Vocational adjustments offer an interesting study … (a) the youth who knows in advance that this handicap will exist and must be reckoned with, and (Z>) the adult whose trade has already been learned and for which his impairment now suddenly unfits him. Type a: For any young man, the outlook is by no means bad. There are relatively few trades or professions in which impaired hearing is of itself a great handicap, once the social and individual adjustments have been made. For instance, in the practice of medicine the expert mechanics of a back brace, of a tonsillectomy, of an ocular refraction or of an appendicectomy are not affected by one’s auditory capacity. Type &: For the adult who has learned a trade in which good hearing is essential, a change must be made, and this is hard. Also, the deafened should “secure work where the hearing will be best conserved.”11 Experts in vocational adjustments for the hard of hearing12 urge that a man do, if possible, what he is really fond of. But without a great urge toward one specific trade, the hard of hearing man would be foolish in this keenly competitive age to burden himself with a known handicap, for there are so many tasks where good hearing, though an advantage, is not essential. It has been pointed out and should be emphasized that the difficulty one thinks of when the vocation of a hard of hearing man is discussed is chiefly a social and psychologic rather than a vocational difficulty. If he can read and carry out his written orders or understand his foreman, his deafness makes him a no less skilled craftsman. In business and the professions, assistants with normal ears are available to make up completely for the individual lack. In most instances, the problem is one of human intercourse. When these social adjustments have been made, the handicap is largely taken care of.
11 Phillips, W. C., and Howell, H. G., Your hearing: How to preserve and aid it, New York, 1932. 12 Peck, Annetta “W., Samuelson, Estelle E., and Lehman, Ann, Ears and the Man: Studies in social work for the deafened, Philadelphia, F. A. Davis Co., 1925. Not Always a Liability. Indeed, impaired hearing may be an asset rather than a liability. A deafened bookkeeper or machine operator minds her business and does not spend her time or her neighbor’s time in gossip. A handicapped laborer who knows a trade will tend to stick on the job and not leave in search of an easier and better paid task. Three assets may be mentioned: (a) Deafness decreases distractions and increases concentration; (&) it fosters constructive thought, though unfortunately the person may not have the creative genius to respond, and (c) it can and in some cases it does increase the interpretative capacity of the other senses. When seeing an expert lip-reader perform, one realizes at once that here is a keenness of visual perception and appreciation that is well-nigh past comprehension. It is questioned as to whether the actual sense responses are made keener. Certain it is that the mental appreciation of what one touches and sees can be increased. Is it not possible that vocations demanding keenness in color combinations or in perfumery perception or in taste blends or in tactile acuity will find the best performers in the ranks of the hard of hearing? Nature delights in compensations. Does not he who conquers an adversity, never mind of what nature, build for his soul a “statelier mansion”?
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