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proper corporate officers, superintendents, department masters, and others, whose duty it is to employ, superintend and direct the men in the machine shops and on the road; and that the employe be informed of these facts, and of the dangers which deafness brings to those placed under his professional care, to the corporation, and to himself. And the opinion was expressed, that you would do well to make certain suggestions which the corporation should adopt for its own protection, such as the following:
All applicants for employment in the machine shops or on the road,-in consequence of whose deafness, loss of life, limb, or property might occur,-before being engaged, should be pronounced duly qualified by the aural surgeon of the company.
All candidates for promotion from the machine-shops, or elsewhere, to positions on the locomotive-engines; and from the position of locomotive-fireman to that of engineer, before receiving promotion, should be pronounced duly qualified by the aural surgeon.
All employes, in any position whatever, in consequence of whose deafness, loss of life, limb, or property might occur, should report at stated intervals to the aural surgeon for his examination.
If, on examination, deafness be found so profound as to otherwise endanger the life of the employe and that of others placed under his official care, he should be told thereof, warned, and, if necessary, be forthwith relieved from duty to undergo suitable treatment.
If, in the faithful discharge of his duty to the company, the employe become permanently disabled by deafness, he should not therefore be dismissed from the company's service to earn his daily bread, at the risk of his life and that of others, on some other road; but the company which he has so faithfully served, should consult its own best interests by pensioning him, or else providing remunerative employment for him in some other suitable position where no special danger will attend his deafness.
Lest the services of a qualified applicant or employe be lost, or an unqualified one engaged, the company should take the precaution to have these aural examinations properly made.
The plea was concluded with an exhorta
tion to obey, in this matter, the official order that reads, "REMEMBER THE RULE THAT REQUIRES ALL EMPLOYES, IN ALL CASES OF DOUBT, TO TAKE THE SIDE OF SAFETY."
That paper seemed so far to express your own views as to have been deemed worthy of your own publication and distribution to every Railway Manager in the United States.
Some of the little seed thus widely sown by you seems to have fallen upon good ground, and has sprung up, bidding fair to bring forth fruit an hundred-fold. Many roads, as I have been credibly informed, now require as a qualification for service in their employ a certain degree of hearing power, under prescribed methods of testing. The assurance, by suitable tests, of the employe's hearing power, as essential to the more safe management of railroads then first proclaimed by your respected body has thus been practically acknowledged by Railway Managers--one more confirmation of the prophecy made before your association in 1891 by our esteemed Dr. Outten: "The officials of railway corporations will see the time has come when the physician will not only be an essential, but an economic factor in the operation of any railroad system." They have heard your voice; they have felt your influence; they have acted upon your advice. And as this is a just occasion for felicitation to you, may it stimulate you to speak once more to those who have shown their willingness to act, under guidance of your better judgment, in this matter, to those who, recognizing the necessity of separating the grain from the chaff, but unskilled in the use of auditory tests, have begun to wield the flail to their own injury and greater danger! "Unqualified activity, of whatever kind," said the great German poet, “leads at last to bankruptcy." Recollect that you suggested this: "Lest the services of a qualified applicant or employes be lost, or an unqualified one engaged, the company should take the precaution to have these aural examinations properly made." How, then, can it take this precaution without your further guidance? It seems that your Association, as such, has not proclaimed its views in pursuit of this end.
Who could have heard unmoved the remarks of Doctors Hoy, Welch, and Outten upon the subject of the inefficacy of the
prevailing methods of testing the hearing of railway employes?
Right here, I beg to disclaim all desire to cast the slightest reflection upon any who approve of and cling to methods of whose disadvantages they have not yet been made. sufficiently aware; but would rather direct your attention to certain features of the matter of testing the hearing, which, in my opinion, may be of practical value toward enabling you to solve this problem aright-for, until it is so solved, it will continue to vex all parties concerned. Of the desirability of the end, there is no question; of the means at present employed, there is certainly valid ground for question. And I make that statement for the following reason: If the prevailing methods of testing be such as to afford no guarantee against the loss of the services of a qualified applicant or employe, nor assurance of the rejection of an unqualified one, surely they are inefficacious, or inadequate. Now, such is indeed the fact. For, on careful study of the tests employed by the different railroads, so far as I have been able to learn them, I find that under any of them, you would reject one of the most reliable employes now in service if he applied for a similar position upon your road; that you would accept another, almost totally deaf without the artificial drum-head of cotton which he now wears with hearing beyond exception. Under the prevailing tests, you would have had to retire from service an engineer whose hearing was so impaired as to have rendered his ranking officer unduly, but, fortunately, unnecessarily anxious, who continues in service with safety. And I can cite you a case of a train-dispatcher whose deafness, until quite recently, has been unsuspected; who was relieved of duty at his own request; who can hardly hear a shouting voice a foot or two from either ear; who is wholly deaf to the tick of a forty-eight-inch watch on closest contact; but who claims to hear the "ticker" at his office, and the human voice-as I findby lip-reading, so as to attend to his business without mistake or complaint. Again, if a skilled mechanic or engineer should apply for a position, you could not determine, with the prevailing methods of testing the hearing, whether his marked deafness, if such there be, is due to the usual accommodation
of the healthy ear to his business conditions, or due to a dulling of the auditory perceptive apparatus from perhaps advanced but unsuspected Bright's-disease. With watch and voice tests, you could not distinguish. To do so, you would have to employ also at least tuning-forks. And if you should accept or reject such applicant upon these watch and voice tests alone, you would make either a most fortunate guess or a very serious blunder. Under the conditions imposed upon an ear in railroad service, it becomes modified in susceptibilty and structure, which disqualifies it for normal audition in ordinary quieter surroundings elsewhere. If the ear be perfectly healthy at the time of entering train service, and if no inflammatory action supervene, the functional modification is established slowly, and to a degree advantageous only to him as an employe, since his ear acquires power to resist the noxious influences of exposure, while retaining in its new circumstances ability to hear ordinary sounds-such as, for example, the human voice-a thing which here is beyond the power of an ear whose hearing is normal under other circumstances. This condition is so well defined in metal-hammerers, engineers, and mechanics generally, that it seems permissible to term an ear with such modified functions a "mechanic's-ear." instance of this condition may be found among boiler-makers, who at work converse in an ordinary tone of voice, which is inaudible to another person present whose hearing is normal in ordinary quieter surroundings elsewhere. Perhaps a better illustration is this: if, in a quiet place, a remark in a low tone of voice be addressed to a rather deaf boilermaker and yourself, you, and not he, will hear it; while if you both now go close to boilermakers at work, a similar remark, made in the same low tone of voice, will be heard by him and not by you. Now, to distinguish a "mechanic's-ear" from one affected by disease, is impossible with the office tests by watch and voice alone; and as it is desirable, even essential, to make this distinction, or to determine just how far such changes in the hearing are advantageous, as arising from the adaptation to habitual environment and extraordinary duty, or disadvantageous, resulting from morbid processes, such tests as are necessary to determine this should be em
ployed in all doubtful cases, i. e., cases which fail to satisfy the scale of hearing prescribed as qualifying for audition, in ordinary surroundings. In fact, when you consider the cases to which I have already alluded, where the prevailing tests with voice and watch alone would have proven wholly misleading and subversive of the advantages of testing the hearing at all, it would seem that we cannot be too careful and thorough in our methods; and if the necessary methods are so intricate as to require a special preliminary education therefor on the part of those whose duty it might be to make such examinations, this work should be assigned to such only of the railway medical staff as are willing and able to devote sufficient time and energy to such essential preparation.
In other words, prudence requires that these examinations should be properly made; for an inefficacious or inadequate test is worse than none.
Tests should be made with watch, voice, and whisper; high and low tuning-forks, and suspended steel rods. The ear should always be inspected; and the functional condition of the Eustachian tube should be determined.
As the degree of hearing, in many cases, varies in different surroundings, the examinations should, if possible, be made in the same place-preferably in that identical place where the examiner has tested the normal ears in determining what is normal for his own watch, voice, and whisper, tuning-forks, etc. For, in methodical testing, each observer must test his own instruments upon a large number of healthy adult ears, and therefrom deduce a normal standard, with which to compare the results of all subsequent examinations. certain percentage of the normal hearingpower having been determined upon as essential to qualification for employment with the company, each examiner can adapt this to his own testing instruments, in due proportions; and he must bear in mind that the hearing-power varies directly as the square of the hearing-distance of a sonorous body from the ear. In using the fractional form of prescribing or recording the degree of "hearing," either "hearing-power" or "hearing-distance" should always be specified, lest mistakes arise from mistaking the meaning of the term,
"the hearing," and substituting the "hearingpower" for the "hearing-distance"-a serious difference, since one of these is the square of the other.
In testing, regard should be had to the fact that the two ears should act in conjunction. The auditory field of each ear overlaps the median plane by about twenty degrees. This gives a field of about forty degrees, for normal ears, along the median plane, a field in which double hearing enables the hearer to determine the direction of a sound without turning his head, and in which he is doubly warned against approaching danger from sonorous bodies, both in front and behind. In affections of hearing where these auditory fields, right and left, are so narrowed as not to meet and overlap at the median line, this advantage is lost; and instead of being able to recognize approaching danger best, when head-on, and to direct either ear at will for its best service, without exclusion of the other, by turning it slightly toward the source of sound, the sound is either unnoticed, or, if noticed, the defective hearer must turn one ear toward it so far as to exclude the other ear from joint service. Hence the suggestion, to determine whether the auditory field be contracted, and whether the two ears act best in conjunction; and, if not, whether the defect be of a degree or character sufficient to disqualify. The observer, therefore, should use the watch and voice tests, not only in the axis of best hearing opposite the ear, but clear to the limits of the normal auditory field, both in front and behind.
In testing with the watch, it should be remembered that it gives out but two sounds of a certain pitch, which are ofttimes unheard by an ear whose conducting or perceptive apparatus has been impaired; and yet, this very same ear may hear the tick of another watch of different pitch, and similar sounds,-as with the train-dispatcher mentioned above, who could hear his office "ticker," although deafto my forty-eight-inch watch, even on pressure-contact. By using a stop-watch, you can readily determine whether or not the examined hears its tick, as he will have nothing but his hearing to aid him in determining whether or not the watch be going.
The watch test alone is of little value; and there is no constant proportion between the
reduction of hearing the watch and that of hearing speech. Bear in mind that the noisier the occupation in which the employe has served, the less will probably be his hearing for the watch, when in a quiet place.
The most popular and important test, for ordinary, practical purposes, and especially for those depending chiefly upon speech and conversation, is that with the human voice. As no two persons possess voices of equal acoustic quality, and, as the various wordsthe vowels and consonants-employed in verbal tests have different logographic value, it is absolutely impossible to establish a satisfactory uniform standard for the voice test. "Such words as chair, horse, and house, are heard three times as far as time and tear. In testing with the voice, therefore, words should be selected for their logographic value, and so arranged as to form sentences for which the listener is unprepared, and such as cannot be constructed by logical inference or intelligent guesswork when some of their parts only are heard. In preparation of a list of such verbal tests, you will doubtless be greatly aided by consulting the articles of Drs. A. H. Buck and Clarence J. Blake, in the Transactions of the American Otological Society for 1876 and 1881, where you will find a table from which to select materials for a list of test words and sentences, based upon intensity rather than upon pitch of the voiceforce producing them, and serving, as in case of chronic catarrh of the middle-ear, as a measure of obstruction of sound. It should be remarked, that these test-sentences should be constantly interchanged, that they may not become familiar to anyone who may possibly have to be tested later. It is necessary that the examiner should test these sentences upon healthy ears first, to determine the normal hearing-distance of his own natural voice for these various words and sentences, so that he may be able to make intelligent comparison of these with the results of subsequent examinations. Owing to the damping of vowels (which are more sonorous than the consonants) by lowering the voice or whisper, the consonants have better chance to be heard; and, as the vowels are "quelled," the consonants become relatively more distinct. In consequence, the deaf can usually hear a moderately loud voice more distinctly than a shouting one.
In testing, therefore, be careful not to raise the voice too high; and in conversation where the deaf are present, "Do not elevate the voice too high, when you wish to make a deaf person hear, but do not lower it too much, unless to a whisper, if it is not desired that he should hear."
In testing, use every precaution to exclude the hearing of the ear not tested; to prevent the examined from lip-reading; and do not fail to determine the degree of bone--or tissue-conduction in the case examined, of which account should always be taken in determining the power of hearing by air-conduction. The bone-conduction for a whisper is less than that for a spoken word; yet the deaf "can often distinguish words spoken in a whisper better than when they are spoken in a low tone of voice." The reinforcement of the sound of the voice, on one side more than on the other, by bone-conduction, can readily be determined with tuning-forks; a vibrating, low-pitched tuning-fork, the handle placed against the teeth, or vertex, being heard louder in that ear which is reinforced the more by bone-conduction,-assuming, of course, that the auditory perceptive-apparatus is equally sound upon the two sides. But that that may not remain a mere assumption, it is advisable that both high- and low-pitched tuning forks should be employed in testing,-after having first been used upon healthy ears to determine the normal hearing for them both by air- and by boneconduction. A comparison of the time during which these forks are actually heard (both by air-conduction and again while in contact with the bones of the head,) with the time in which they are similarly heard by the normal ear will enable you to form a precise idea as to the location and degree of the defects. In other words, by this, the so-called Rinnè's method, we "may discover the conditions of the sound-conducting and sound-perceiving parts, either singly or combinedly, as well as their relative quota." As to this test, the committee of the American Otological Society, appointed to examine and report on "The Examination of the Power of Hearing and How to Record its Results," made this statement: Rinne's method is the most expeditious and practically the most important. It should be employed in a routine way, just as the watch and voice tests, in every case where impair
ment of hearing comes into question at all.' The use of vibrating, suspended steel rodsthe Koenig's rods, so-called-of a range of 20,000 to 60,000 vibrations a second, will enable you still more surely to determine the location, nature, and degree of an abnormal process impairing hearing.
One might question the necessity of introducing these latter tests; but when I report that two cases of far-advanced Bright's-disease, hitherto unsuspected by the examined and his physician, have been detected through an examination made by me with these instruments, although the hearing had not become impaired so far as to disqualify under prevailing watch and voice tests for railway employes, I think you will not lightly reject them.
The condition of the Eustachian tube should be considered; as, if the tube be closed, the hearing may be so affected as to disqualify an employe or applicant who might pass muster if only the tube were first opened and the tympanum, inflated.
Above all, the ear should be inspected. The presence of "wax" in the ear, even where the hearing is still normal, is a dangerous condition; as, by the swelling of this "wax," or by its displacement against the drum-head, deafness may suddenly occur. In one case, to my knowledge, an engineer was nearly thrown from his seat by sudden vertigo, caused by displacement of wax and its impaction against the drum-head. In one of the cases above cited, where deafness was almost total without an artificial drum-head of cotton. worn with almost normal hearing-no discharge from the ear having been seen for over thirty years the individual would undoubtedly be pronounced qualified under the prevailing tests, provided no inspection of the ear were made. Yet, such a man would be a very unsafe employe in train service, as a slight displacement of his artificial drum-head might be attended with sudden and profound deafness.†
In testing with the voice, you will find that *Transactions of the American Otological Society, 1887, p. 22 +Rupture of the drum-head of one ear, affected by chronic catarrhal inflammation, by blowing the whistle of his engine while passing under a roadway, with subsequent increased deafness, happened to Daniel McLaren, Esq., later President of the Cincinnati Hamilton and Dayton Railway Company. (S. Sexton, M. D., The Ear and Its Diseases, New York, 1888, page 217.) Had the custom of periodic expert aural examination and inspection of railway employes been established at that time, Mr. McLaren would doubtless have escaped this accident, through previous warning as to the weak condition of his drum-head.
the sound of the letter "B" is heard less and less, proportionately to an increasing loss of the drum-head of the ear. In cases showing this reaction to the vocal test, therefore, be sure to look carefully for this condition-a perforated drum-head. Inspection will aid you in recognizing many conditions where the hearing is sure to be variable; and these cases demand careful study and thought before being finally passed upon by you.
So much for the methods of testing the hearing and examining the ears.
Experience has shown conclusively that, although the method of testing the hearing at one's office should be the same for all, the required percentage of hearing for applicants (unless they be already inured to noisy occupation) is inapplicable to the trained, educated mechanic and the locomotive-engine employe. The required degree of hearing for such men. should be a special one; that required of train-dispatchers and of telegraph operators should be different from that required of engineers, firemen, and others of the train-crew. The required degree of hearing should vary with the different branches of the service: a special one being prescribed for each set of employes in consequence of whose deafness loss of life, limb, or property might ensue. This scale cannot be accurately determined instanter. If worth doing at all, it is worth doing well; and, better, still later; and, again; until finally done right. If hearing is to be tested and a degree of normal hearing to be prescribed as a qualification for active duty. in railway service, why! in the name of common sense, let the tests, the methods of examination be efficacious and adequate; and the required degree of hearing for the various branches of the service be graduated and adapted more suitably to each "that the services of a qualified employe or applicant be not lost, nor an unqualified one engaged."
It seems, too, that the end aimed at might be attained better, and, perhaps, more quickly, by a concerted movement on the part of railway managers, their surgeons, and their otological specialists, toward the establishment of more satisfactory and uniform methods of testing the hearing and examining the ears of their applicants and employes; and to determine, more to their advantage, a scale of required hearing under those tests, more suit