PART IV. BEAF-MUTEISM AND HEARING TRUMPETS. (Part 1)

PART IV. BEAF-MUTEISM AND HEARING TRUMPETS. CHAPTER XX. DEAF-MUTEISM— HEARING TRUMPETS. Deaf-muteism is caused by diseases of the middle and internal ears. These diseases are of various kinds, and have been fully discussed in the preceding chapters of this work. The only reason that deaf persons become mutes is that the disease of the ear occurs either before birth, or so shortly after, that its victim is unable to learn to imitate speech. There are no changes in the larynx that prevent deaf-mutes from articulating distinctly, except those that may possibly come from disuse of the organ. Persons who become completely deaf later in life, do not lose the power of speech ; but they usually speak in an unna- tural tone, because they are unable to hear their own voice with distinctness. Deaf-mutes may be divided into two great classes. I. — The acquired cases, or those in whom the disease of the ear has occurred after birth, from some traceable cause. II. — The congenital cases. It is very difficult to come to a correct conclusion as to the relative frequency of congenital and acquired deaf-muteism. The tables that are made up by the directors of schools for the deaf and dumb are not trustworthy, because they are taken from the statements of persons who are seldom exact observ- ers— the parents or friends of the children. Dr. George M. Beard and myself* examined two hundred and ninety-six cases of deaf-muteism, with their histories, in the schools of New York City, and Hartford, Conn., and the result of our examination was, that about sixty-one per cent, of these cases * American Journal of the Medical Sciences, vol. liii., p. 401. 550 DEAF-MUTEISM. were probably congenital, and that the remaining thirty-nine per cent, were acquired. Wilde's statistics show that about fifty per cent, are of the acquired form. The exact truth as to the time when the deafness occurred, is something very difficult to ascertain. It is not easy to learn, even when great pains are taken by persons well competent to observe, whether a very young infant hears well or not, although we may easily satisfy ourselves whether or not loud sounds are perceived. "Wilde* says that children appear to be conscious of sounds during the third month, while at the fourth they show an appreciation of particular sounds, such as chirping, whistling and the like. He believes that from the fourth to the sixth month is perhaps the earliest period at which an opinion can be formed as to the hearing of an infant. Moreover, an inflammation of the ear, if not of the suppurative variety, may run its entire course in a young child, and never be recognized by physician or friends as a case of aural dis- ease. It is well known, and the fact has been before alluded to in this volume, that a suppurative inflammation of the mid- dle ear, in an infant, is sometimes first recognized as such when the pus breaks through the membrana tympani. The fact that such severe processes may go on in the ears of chil- dren, and escape recognition, renders it very probable that even Wilde's proportion, in which he gives fifty per cent, as the proper one for acquired deaf-muteism, is too low a one. I am inclined to think that there are many more cases of chib dren becoming deaf after birth, than of intra-uterine deafness. It does not require absolute deafness in a young child to produce deaf-muteism. A case of chronic aural catarrh, that would only inconvenience a grown person, will make an infant so stupid that it will soon cease to attempt to imitate speech. We have all grades of hearing power in so-called deaf-mutes. I have seen two or three cases of children who were being educated in deaf and dumb asylums, who could hear words spoken into their ears in a very loud tone. In one case the parents found it too much trouble — inasmuch as no physician could be found who would treat the suppurating ear — to teach * Aural Surgery, English edition, p. 461. DEAF-MUTEISM — CAUSES. 551 their child to speak. He was consequently losing his speech, and also having his life placed in peril by the neglect of the ulcers in his ears. Causes. — The causes of deaf-muteism are very graphically set down in the reports of deaf and dumb asylums, but unfor- tunately these assigned causes are usually incorrect. Thus, " colic," " a burn," " a fall," " fits," " mother marked,"* etc., figure in such tables as causes of deaf-muteism. Many of the so-called facts in such tables have been derived from unscien- tific observers, who sometimes have very positive opinions as to the causes of disease, and who believe that in a severe fright to the mother, the marriage of cousins, etc., ample causes are found for deaf-muteism. The investigation of the proximate causes of deaf-muteism, show, as has been said, that their victims have become deaf from precisely the same kinds of disease, and in about the same proportion as obtains in impairment of hearing or deafness occurring at a time of life that prevents the subjects from becoming dumb as well as deaf. Of the 296 cases examined by Dr. Beard and myself, in only 22 cases was the drum-head found to be normal, and in 200, or more than two-thirds of the whole number exam- ined, there was chronic pharyngitis or tonsilitis. . It is thus seen that the middle ear was usually the seat of the lesion that caused the deafness. Of the 114 acquired cases, the membrana tympani was perforated in twenty-nine cases. Thus, suppurative inflammation does not seem to cause as large a proportion of deaf-muteism as is usually supposed. In some of the cases, however, the membrani tympani had once been perforated and had healed. In Blake's statistics, t forty per cent, of those examined, forty-one in number, were classed by him as acquired cases. In twelve of these acquired cases the membrana tympani was perforated or destroyed on one or both sides. In thirteen of the seventeen cases, the deaf- ness was traceable to the pharyngitis of scarlet fever or measles. * On the Etiology of Acquired Deaf-Muteism, by Clarence J. Blake. Reprint from Boston Medical and Surgical Journal. f Reprint from Boston Medical and Surgical Journal. 552 DEAF-MUTEISM. The remote causes, or the causes that tend to produce disease of the ears in intra-uterine or infantile life, form a very interesting study, but we have as yet no very accurate data upon which to discuss them. It is an open question, perhaps, whether intermarriage tends to produce disease of the ear in young subjects or not, or whether it tends to lead to arrested development in young children ; for there is no doubt that some cases. of congenital deafness depend upon want of proper development of the auditory nerve and laby- rinth. I was informed at Hartford, that a certain part of our country, which is somewhat isolated from the other parts of the Union, and where intermarriages are the rule, furnished a proportionately large contingent of cases of congenital deaf- muteism. The cases from this district that I saw, were in persons somewhat deficient in intellect, and we may consider their etiology as identical with that of idiocy, feeble brains, or partial development of other parts of the body, such for example, as spina bifidis, coloboma iridis, etc. Yoltolini's inflammation of the membranous labyrinth is probably one of the proximate causes of acquired deaf-mute- ism. Von Troltsch showed that a purulent process is a very common appearance in the tympanic cavities of half-starved foundlings. I suppose that the mal-nutrition of parents may be traced as remote causes for such affections of the middle ear. We may sum up the causes of deaf-muteism, as developed in clinical histories and in examinations on the dead subject, as follows: ' 1. Inflammation of the middle ear, resulting in suppura- tion, or adhesions, anchylosis of the ossicula auditus, etc. 2. Inflammation of the nerve or labyrinth, resulting in suppuration or thickening of the membranous labyrinth, deposits in it, etc. 3. Arrested development of some parts of the essential part of the auditory apparatus, for example, absence of the semicircular canals, or of the cochlea. These are the causes which are shown in the table given by Moos,* in his account collected from various authorities, of * Klinik der Olirenkranklieiten, p. 341. DEAF-MUTEISM. 553 sections of the ears of sixty deaf-mutes, and they agree we]] with the clinical examinations and histories. Treatment. — There is certainly no peculiar treatment neces- sary for the deafness of young children, which renders them mute, because they cannot learn to imitate speech ; but I can- not refrain from alluding to the lingering remains of the bar- barism of the past centuries, which neglects the care of the ulcerated membrana tympani, and the swollen throats of the poor mutes who suffer from chronic suppuration and catarrh of the middle ear. Although the educational wants of deaf- mutes are now well attended to, their medical treatment is sadly neglected in the asylums and schools of our country. It was not until the seventh century that deaf-mutes were thought worthy of an education. The twentieth century will probably arrive before every school or asylum for these unfortunates has in attendance a physician who knows how to examine and treat a diseased ear. These schools are not hospitals, it is time ; but there is always in them quite a large proportion of young patients, who still suffer from a disease which, although it has fully destroyed the hearing, is not yet stayed, and which often goes on to destroy life. I refer, of course, more particu- larly to the suppurative forms of disease. According to the census of 1870, there were in the United States, sixteen thousand two hundred and five deaf-mutes : of these we may believe that fifty per cent, belong to the acquired cases. How many of these belong to what may fairly be called preventable diseases, it would not be possible to say ; but certain it is, that if diseases of the ear had always rejoiced in the same attentive treatment as many of the less essential parts of the body have received, the number of these unfortu- nate mutes would have been greatly lessened. HEARING TRUMPETS. We have not, as yet, been furnished with an apparatus for conducting the undulations of sound to the ear, which is at the same time efficient and unconspicuous. This is the great de- sideratum of most patients who are affected with incurable 554 HEABENG TRUMPETS. impairment of hearing, for nearly all deaf persons would like to conceal their infirmity. It is possible that the development of the science of acoustics will yet furnish us with a sound lens, that will refract and focus rays of sound upon the drum-head and assist the hearing power ; but in the very nature of things it is not likely that we shall ever have an apparatus so well adapted to the pathological changes in a diseased ear, as are convex lenses to the physiological process of thickening of the crystalline lens and rigidity of the ciliary muscle, which we term presbyopia. The physician can only therefore advise his patients to use one of the simple conductors of sound that are here delineated, as being all that science, as yet, offers to the hopelessly deaf. Fig. 110. Hearing Trumpets. It will be seen that the first is a flexible speaking tube, which is very convenient for conversation, and is in fact called a conversation tube. The second and third figures represent the ordinary metallic trumpets which aid many persons with impaired hearing to hear addresses, sermons, and so forth. In many churches long flexible tubes run from beneath the pulpit to the seats of those whose hearing is impaired, and are used as is the conversation tube. I am very much in doubt as to the value of the so-called auricles, represented in the fourth figure. The most different accounts are given as to HEARING TRUMPETS. 555 their value as assistance to the hearing power. They are, of course, worn over the head and fit into the meatus. The simpler apparatus are usually the best. It is some- times of advantage to use little clamps which hold up the auricle, as deaf people do with their hands, in order to catch all the waves of sound. The small " invisible " tubes, placed in the auditory canal, are wholly useless. There is, in fact, no apparatus as yet invented that is better than the various forms of curved tubes» DESCRIPTION OF THE CHROMO-LITHOGRAPHS. Fig. 1. — Normal menabrana tympani. It is impossible to exactly render the normal tint of this beautiful struc- ture, but this lithograph seems to me to approximate this to a very satisfactory degree. Fig. 2.* — In this case, that of a man thirty-two years of age, a purulent inflammation of the middle ear had existed for nearly two years. There was a perforation in front of the malleus, which finally healed under the applica- tion of nitrate of silver, forming the cicatrix shown in the drawing, and also a small circular opening through the " pars flaccida " — the space within the open- ing, and around the malleus-incus articulation being filled with small granu- lations. After the closure of the lower perforation, these were treated by application of saturated solution of arg. nit., on a cotton-tipped probe, with good result. ' The outer layer of the mem brana tympani, above and behind the processus brevis, was much thickened and congested, and this condition (as shown in the drawing) continued after the closure of the inferior perfora- tion. This plate is of value, as exhibiting a comparatively rare form and position of perforation of the membraua tympani, and one not readily amen- able to treatment. Fig. 3 represents a small perforation, the consequence of purulent otitis media, occurring in a boy twelve years of age, and of one year's duration. There were no granulations at the time when the drawing was made, and the perforation was in process of healing, as is shown by the congested blood-ves- sels extending from the periphery towards the perforation. This drawing exhibits the want of clearness of the outline of the malleus, as the result of thickening of the outer layer of the membrana tympani, and also the promi- nence of the processus brevis and of the posterior fold, in consequence of the concavity of the membrana tympani. Through the perforation is seen the congested mucous membrane of the middle ear. * The cases here described were treated by Drs. C. J. Blake and H. L. Shaw, of Boston. 558 DESCRIPTION OF THE CHEOMO-LITHOGEAPHS. Fig. 4. — A case of purulent otitis media, in a boy twelve years of age. This drawing represents faithfully the granulations occurring on the mem- i brana tympani, and also the thickening of the membrana tympani, subsequent to the perforation, and during the continuance of the purulent inflammation. This case was convalescent at the time the drawing was made, under the application of astringents to the middle ear, and the granulations were rapidly diminishing under the application of arg. nit. In this drawing, also, is shown the peculiar arrangement of the bloodvessels passing from the superior wall of the meatus into the membrana tympani, to assist in forming the manubrial plexus, and which are congested in consequence of the diseased condition of the tympanum and membrana tympani. Fig. 5 represents a case of chronic catarrhal inflammation of the middle ear, accompanied by great concavity of the membrana tympani. The proces- sus brevis is very prominent, and both anterior and posterior folds of the membrana tympani are consequently elongated. The handle of the malleus is much foreshortened, and the lower end nearly in contact with the promon- torium, as is shown by the lighter color of the membrana tympani at this point, the light rays being reflected directly from the white surface of the pro- montorium. The concavity of the membrana tympani is further evidenced by the character of the light reflection, which, instead of being a perfect cone, as represented in Fig. 1, is represented by two small points of light, one close to the end of the malleus, and one at the periphery ; the intermediate space repre- senting a surface of such degree of concavity that the light thrown upon it from the mirror is focussed at a point within the meatus. Fig. 6 is a type of cases of chronic catarrhal inflammation of the middle ear, of long standing, in which the mucous coat of the membrana tympani has become uniformly thickened, with but a slight degree of concavity of the membrana tympani ; the latter condition in this case is principally evidenced by the prominence of the manubrium and processus brevis, and of the poste- rior fold. The same dull gray color is found, as a result of thickening of the mucous coat of the membrana tympani, following acute inflammation of the middle ear. This drawing exhibits also the appearance characteristic of, and the form peculiar to, large calcareous deposits. The light reflex is wanting, in conse- quence of the presence of the calcareous deposit at the point at which this appearance is found in the normal membrana tympani. Fig. 7 represents a condition common to chronic catarrhal inflammation of DESCRIPTION OF THE CHROMOLITHOGRAPHS. DDV the middle ear. In this case the malleus is in contact with the promontorium, and the continuance of the atmospheric pressure from without has carried the membrana tympani inwards, rendering the malleus exceedingly prominent. The light color of the central portion of the membrana tympani is due to the reflection of light from the inner wall of the tympanum, and not to thickening of the mucous