CHAPTER XIX. DISEASES OF THE INTERNAL EAR. (Part 4)

— Partial Delirium — Deafness in a few Days — No Paralysis — Recovery from all Symptoms but Deafness. Sally A., set. 13, May 3, 1873. Three months ago this child was attacked with vomiting and pains in the head. She became only slightly delirious. There was no paralysis of any kind. The hearing was found to be impaired in a very few days, and she became deaf soon, and has remained so. She was taken sick on Saturday, and on Wednesday she heard as badly as now. She is now perfectly deaf, but concussions hurt her ears. She walks with difficulty, that is, the gait is staggering. Primary Labyrinth Disease. March 25, 1872, Martha , ast. 11, when 16 months old, had some kind of convulsions, and since has been deaf. Had spoken words and given other evidences of hearing before this. She never had any disease of the head, nor discharge from the ear. She cannot now hear the ticking of a watch, nor words spoken into the ear ; but the vibrations of a tuning-fork are plainly perceived. Both membranaa tympani are sunken. Inflammation of Labyrinth from Cold, Induced .by Lying Down while in a State of Perspiration. June 9, 1873, Geo. O'B. , set. 31, agent, one day last summer lay down while in a state of profuse perspiration. The next day he observed a singing noise in his right ear, and that then he did not hear well on that side. There were also darting pains across his head and the back of the auricle. Is anxious and worried. States that he had an acute inflammation of the head some time since. Hearing distance : right ear, 0 ; left, $f. The membranas tympani show no signs of disease. The tuning-fork is heard most distinctly on the left side. Pain — Paralys is— Deafness. Maria L., aat. 3, when two years and a month old, awoke one night scream- ing with'pain. She did not roll her head, or become unconscious, but lost power over her limbs, and had general febrile excitement. She was ill for one week, but it was two months before she could walk. On recovery, she was found to be deaf, and is now almost, if not entirely, devoid of hearing. The membranaa tympani of each side altered in curvature and color. The practitioner will judge for himself as to how much inflammation of the spinal cord, or membranes of the brain, there is in such cases as these. CONCUSSIONS. "Workmen employed in hammering large iron plates, such as are used in making the boilers of steam-engines, are very CONCUSSIONS. 509 apt to lose much of their hearing power. So many of these cases are seen at Ear Infirmaries, that at one time " Boiler- makers' Deafness " figured as a separate disease of the ear in the statistical reports of one of our institutions where aural disease was treated. Examination of such cases has shown me that the lesion causing the impairment of hearing and deafness must be sought for in the labyrinth, and that it is probably due to concussion of the fibres of the nerve in the cochlea and semi- circular canals. Concussions of the labyrinth, from cannonading, such as are sometimes experienced by soldiers and sailors, the impaired hearing and extreme sensitiveness of the ears sometimes ob- served in telegraph operators, belong to this class of labyrinth affections. Deafness from such concussions, without an affec- tion of the tympanic cavity, is very rare, however. There can be no hesitancy in believing that the continual recurrence of a kind of sound, that has no musical, but, on the contrary, an unpleasant character, must at last cause a hyperse- mia of the ultimate nerve-fibres of the cochlea. The incessant shock of the drum-head by the blows from dozens or even hun- dreds of hammers upon vibrating plates must agitate these fibres in such a manner as to finally put them out of tune, as certainly as the constant use of a piano will at last loosen its strings. Clinical experience confirms this view, and my own observations and investigations in reference to boiler-makers' shops seem to demonstrate the following facts : I. Boiler-makers are nearly all hard of hearing ; and those who are not, have, as a rule, taken the wise precaution of plug- ging the external meatus with cotton, so as to diminish the force of the sound-waves upon the drum-head. II. The impairment of hearing is generally attributable to some lesion of the labyrinth, probably of the cochlea ; for the chief symptoms are loss of hearing and tinnitus aurium ; there is no vertigo, or staggering in the gait. Superadded to this serious trouble, tympanic or middle ear catarrh is very frequently present, but these must be regarded as purely coincidental. Boiler-makers are constantly exposed to sudden and marked changes of temperature, and heuce ofteu 510 BOILER-MAKEKs' DEAFNESS. catch cold, intensifying and increasing by this means the aural affection. Should a man, already suffering from disease of the middle ear, begin to work in a boiler-shop, he will, of course, suffer in a much greater degree, and the organ be more susceptible of additional injury, than a man who is in the enjoyment of a sound organ of hearing. Dr. D. R. Ambrose has shown me a case which confirms this view. In the same way, a telegraph operator who has pharyngeal catarrh, and consequently a swelled Eustachian tube, which is not always capable of per- forming its proper function, will be more sensitive to, and suffer more acutely from, the concussions of the instrument, than he who has a healthy throat. The existence of tympanic and tubal catarrh will cause the Eustachian passage to be less pervious, or even at times entirely closed; and thus aggravate the unpleasant conditions existing when waves of sound that have to go but a short distance, and are besides inclosed in tubes, and thus increased in intensity, impinge upon the molecules that make up the ultimate fibres of the auditory nerve. Those who work inside the boilers as riveters, and who thus have shorter waves of sound striking upon their ears, lose their hearing power most completely, as is evidenced by the testi- mony of all old boiler-makers. It is not easy, in the absence of post-mortem investigations, to define the exact nature of the lesion, but it may probably be a passive congestion of the con- tents of the cochlea. If care were taken to deaden the sound - — that is, to interrupt the vibrations by the use of the cotton plug — I have no doubt but that the hearing power of boiler- makers might be materially preserved. One of the cases already alluded to, which will be given below, is a striking exemplification of what may be accomplished in this respect* In studying the cases of boiler-makers' deafness, it will be observed that the subjects of it hear very well in the tremen- dous din of a boiler-shop, while they are quite deaf in an ordinarily quiet place. It becomes an interesting question as * I am indebted to Hon. Robert P. Parrot, of Cold Spring, and Dr. F. D. Lente for the opportunity of seeing these cases. HEARING BETTER IN NOISE. 511 to why this is, or why do any patients with disease of the ear hear better in the midst of noise ? These cases, as has been said in the introductory chapter, were first described by Thomas "Willis in the seventeenth century, but as yet they have not been adequately explained. Although the power of hearing the voice is much improved in many partially deaf people — while in a rail-car or stage-coach, for example, or when a drum is beaten near them, as in Willis's case — the power of hearing the watch, or of hearing the outside or general noise, that of the wheels or the engine, is not im- proved. This fact has not been always appreciated in the study of this subject. The phenomenon of hearing better in the midst of noise also occurs in subacute cases of catarrh, from which complete recovery occurs. This fact has also, I think, not always been recognized in the theories that have been pro- pounded for the explanation of this phenomenon. Relaxation of the drum membranes, rigidity of the base of the stapes, which is the pathological theory at the base of many of these explanations, will hardly be supposed to occur very markedly ill subacute cases of catarrh of the middle ear. The following case illustrates this subject, and, perhaps, may in some degree lead to the elucidation of the problem that has employed several minds. Use of Artificial Drum-heads— Better Hearing in a Noise. A man thirty-six years of age presented himself at my office, saying that he had suffered impairment of hearing as a child from an ulcerative process in both ears. Being a paper manufacturer, he was much accustomed to have bits of paper in his hand, and occasionally he would use them to quiet un- pleasant or tickling sensations in the auditory canal. He thus learned that if he put the paper in far enough and struck the right point, he could hear better. Discovering this, he continued to employ this method for years, and he came to me to know if some better artificial drum-head could not be devised, and also "to instruct the faculty ." I found both drum-heads gone, scarcely a rim remaining ; the mucous membrane of the tympanic cavity was swelled and hypersecretive. The ossicles could not be seen. The artificial drum-heads of Toynbee improved his hearing from ^ to -4iT, and from thirty-four to fifty feet, and more. The interesting fact he stated to me is, that, when he im- proved his hearing for the voice, it was only of use in moderately quiet places ; that is to say, if he went into a rail-car, he needed no help — he could hear the conversation as well, if not better, than those who had healthy ears; but he could not hear the wheels, the engine ; in short, the waves of sound 512 HEARING BETTER IN NOISE. from a distance, or the undulations not produced by the human voice, did not seem to reach his nerve. When he used his artificial drum-head, like ordi- nary people, he had some difficulty to hear, on account of the surrounding Dr. A. H. Buck,* in a review on the progress of otology,, has suggested an explanation for this phenomenon of hearing better in the midst of noise, which he does not claim as his own, but which I am unable to find in any other place. He assumes the pathological condition in these cases to be one of rigidity, either of the ligament which holds the base of the stapes bone, or of the membrana tympani secundaria. He then supposes that wave-sounds of sufficient strength are put in motion by the noises of these noisy places to set the stapes in motion, while it could not be set in motion by the waves pro- duced in ordinary conversation. Once in vibration, this ossicle, which is termed the key to the auditory chamber, can perform, with a certain degree of freedom, the subordinate vibrations called into existence by the conversation which is carried on near by. The facts in the phenomenon of hearing better in the midst of noise are : A certain number of people whose hearing is impaired hear better in a noise than they do in a quiet place, and not only that, but they hear better than people whose hear- ing power is normal. As to the pathology of these cases, we know that this condition obtains in acute, subacute, and chronic affections, suppurative and non-suppurative, of the middle ear, but not in all the cases of these affections, and that it does not occur in diseases of the nerve. The improvement in hearing power in noise seems only to extend to the human voice. The tick of a watch is not heard better or farther in a noisy place than in a quiet one, as I have taken pains to ascertain. Indeed, it is not heard as well. Dr. Buck's explanation does not seem to me adequate to explain all these facts. In the first place, we can hardly suppose " rigidity of the ligament that holds the base of the stapes bone, etc.," to be the pathological condition in acute or subacute catarrh. In these cases, as I have said, as well as in the chronic forms of disease where rigidity may be "New York Medical Record, July 5, 1875. HEARING BETTER IN NOISE. 513 supposed, the phenomenon of hearing better in noise occurs. Secondly, the improvement resulting from "setting the stapes in motion " ought to affect other sounds than those of the voice, which it does not. It will be observed that the patient whose case I have re- ported states that he could not hear the outside sounds as well as people with good ears. He proved this by the fact that when he put in his artificial drum-heads, and became like other people, he was so much disturbed by the sound of the wheels, engine, etc., that he could not hear conversation as well as when they were out and he was comparatively deaf. In this case at least a kind of Daltonism of the ear, an insensibility to certain sounds, was produced. Perhaps, then, the elevation of the pitch of the voice, or what is the same thing, the increase in the number of vibrations in a given time, with a change in quality of the voice of the speaker, taken together with the in- sensibility to outside sounds, enabled this patient to hear better in a noise. If we can successfully imitate this increase in pitch and this assumed change in quality, in a quiet place, of course such patients should hear as well there also. This experiment is necessarily a difficult, but probably not an impossible one. I hope other cases, and the carrying out of the experiment suggested, will finally enable us to explain what is now only a puzzle to most of those who investigate aural disease. Tinnitus Annum, without Impairment of Hearing, occurring from Listening to a Telegraph Instrument — Hyperemia of Acoustic Nerve ? W. G-. B. , set. 37, states that he has been a telegraph operator for about twenty years, and that he has had tinnitus aurium for about two years. Hearing distance : right ff , left ||. Both membranae tympani have good light spots ; there is some granular pharyngitis. The patient is confident that the vibrations of the telegraphic instrument have caused the noise in his ears. The sound of the instrument is very unpleasant to him, and he is obliged to protect his ears, while at work, by cotton plugs. Indeed, his ears have got into such a sensitive condition that jarring sounds of any kind are extremely annoying to him. The patient is in good general health. Impairment of Hearing of one Side, ascribed to Occupation as Telegraph Operator. May 4, 1870. Mr. B., ast. 27, about a year ago discovered that the hear- ing power of his left ear was somewhat impaired. Three months ago he was 514 boiler-makers' deafness, cases. troubled with a continuous noise in that part of his head. He is a telegTaph operator, and has been accustomed to use his left ear — leaning his head over tbe machine on that side and intently listening. He believes that this is the cause of his loss of hearing. The drum-heads look very much alike, both exhibiting peripheral opacities, but in other respects having a normal appear- ance. The pharynx and nares seem to be healthy. Inflation of the ears has no effect upon the hearing. The watch is not heard at all on the affected side, nor is the tuning-fork. Boiler -makers' Deafness — Impairment of Hearing — Absence of Tinnitus Au- rium. W. B., set. 64, has been a boiler-maker for 33 years, and heard perfectly well before he began to work at that business. He has never had '* ear- ache ; " his hearing began to fail him four or five years after his entering the shop. Hearing distance : right -4tt8-, left -4a«. Tuning-fork not heard when the handle is placed upon the forehead, but distinctly audible when placed on the teeth. Membrana? tympani : right, manubrium distinct, light spot of good shape ; left, the same appearances. He has no tinnitus aurium ; he hears conversation better in the noise of a shop than outside, but he cannot hear the watch any farther. Politzer's method does not improve the case or the hearing power ; nor is the air felt to enter the ear. Boiler-maker Eight Years — Gradual Loss of Hearing. Robert B., set. 23, has been in boiler-shop eight years; had heard well before he entered the shop, but he finds that he is gradually losing his hear- ing power. Hearing distance : right 3^, left -fa. Tuning-fork is plainly heard in both ears ; membranes tympani normal in both sides. The employ- ment of Politzer's method slightly improves the hearing. Boiler -maker Thirteen Years— Tympanic as well as Labyrinth Disease. W. B., set. 30, has been thirteen years in the shop, and finds that his hearing is becoming impaired ; had earache occasionally, and a discharge from one of the ears for a short time. Some years ago suppuration occurred, which soon ceased. Hearing distance : right ft, left 43-s-. Tuning-fork heard better in right ear. There is no tinnitus. The right ear drum is concealed from view by hard wax ; the left is normal in appearance. The impairment in hearing in this case was undoubtedly aggravated by a catarrhal process that occurred years before, but