YearNumberNo. perMillion ofPopulation1830 (the deaf and dumb)6,1064751840 (the deaf and dumb)7,6654491850 (the deaf and dumb)9,8034231860 (the deaf and dumb)12,8214081870 (the deaf and dumb)16,2054201880 (deafness occurring under sixteen)33,8786751890 (the deaf and dumb)40,5926481900 (the totally deaf)37,4264921910 (the deaf and dumb)43,812476
From this table there appears to be a steady decrease in the number of the deaf in relation to the general population from 1830 to 1860, this latter year seeming to be the low water mark. From 1860 to 1870 there is a slight increase, and from 1870 to 1880 a very large one, due to some extent to the method of taking the census. From 1880 to 1890 there is a certain decrease, though the proportion is still very high. From 1890 to 1900 there is a very considerable decrease, probably indicating a return to true conditions; and a not negligible decrease from 1900 to 1910.
On the whole, with respect to these statistics, probably the most that we can safely say is that deafness is at least not on the increase relatively among the population, while there is a possibility that at present it is decreasing. For further determinations, we shall have to seek other means of inquiry.
We may perhaps best approach the problem of deafness as an increasing or decreasing phenomenon in the population, if we think of the deaf as composed of two great classes: those adventitiously deaf, that is, those who have lost their hearing by some disease or accident occurring after birth, and those congenitally deaf, that is, those who have never had hearing.[17]In regard to the former class, it follows that we are largely interested in the consideration of those diseases, especially those of childhood, which may affect the hearing, and in their prevention or diminution we can endeavor to ascertain how far there are possibilities of reducing the number of the deaf of this class. In the latter case we are called upon to examine some of the great problems involved in the study of heredity, especially in respect to the extent that the offspring is affected by defects or abnormalities of the parent, and to see what, if any, means are at hand to alter conditions that bring about this form of deafness. We shall first discuss the causes of adventitious deafness, togetherwith the possibilities of its prevention and the likelihood of its diminution, and then consider the questions involved in congenital deafness.
From three-fifths to two-thirds of the cases of deafness are caused adventitiously—by accident or disease. To accidents, however, only a very small part are due, probably less than one-fiftieth of the entire number.[18]Nearly all adventitious deafness results from some disease, either as a primary disease of the auditory organs, or as a sequence or product of some disease of the system, often one of infectious character, the deafness thus constituting a secondary malady or ailment. The larger portion is of the latter type, probably less than a fourth resulting from original ear troubles.[19]In either case deafness occurs usually in infancy or childhood, and does its harm by attacking the middle or internal ear.
From diseases of the middle ear results over one-fourth (27.2 per cent, according to the census) of all deafness, and from diseases of the internal ear, one-fifth (20.7 per cent), very little (0.6per cent) being caused by disorders of the outer ear. Of the classified cases of deafness, according to the census, 56.3 per cent are due to diseases affecting the middle ear, and 42.7 per cent to diseases affecting the internal. Of diseases of the middle ear, 72 per cent are of suppurative character, often with inflammation or abscess, and 28 per cent non-suppurative, or rather catarrhal in character. Of diseases of the internal ear, 89 per cent are affections of the nerve, and 10 per cent of the labyrinth. It is to be noted that when the affection is of the internal ear, the result is usually total deafness.
By specified diseases, the leading causes of deafness are scarlet fever (11.1 per cent), meningitis (9.6), brain fever (4.7), catarrh (3.6), "disease of middle ear" (3.6), measles (2.5), typhoid fever (2.4), colds (1.6), malarial fever (1.2), influenza (0.7), with smaller proportions from diphtheria, pneumonia, whooping cough, la grippe, and other diseases. A large part of deafness is seen to be due to infectious diseases, the probabilities being that fully one-third is to be so ascribed, with one-fifth from infectious fevers alone.
After birth and under two years of age, the chief causes of deafness are meningitis, scarlet fever, disease of middle ear, brain fever, and measles. From two to five scarlet fever andmeningitis are far in the lead, with many cases also from brain fever, disease of middle ear, measles, and typhoid fever. From five to ten scarlet fever alone outdistances all other diseases, followed in order by meningitis, brain fever and typhoid fever. From ten to fifteen the main causes are meningitis, scarlet fever, brain fever, and catarrh; from fifteen to twenty catarrh and meningitis; from twenty to forty catarrh, colds and typhoid fever; and from forty on, catarrh.
The following table[20]will show in detail the several causes of deafness and their respective percentages.
CAUSES OF DEAFNESS
Total classified48.5External ear0.6Impacted cerumen0.2Foreign bodies0.1Miscellaneous0.3Middle ear27.2Suppurative19.6Scarlet fever11.1Disease of ear3.6Measles2.5Influenza0.7Other causes1.7Non-suppurative7.6Catarrh3.6Colds1.6Other causes2.4Internal ear20.7Labyrinth1.8Malarial fever1.2Other causes0.6Nerves18.5Meningitis9.6Brain fever4.7Typhoid fever2.4Other causes1.8Brain center0.3Miscellaneous0.1Unclassified45.3Congenital33.7Old age0.3Military service1.0Falls and blows2.8Sickness2.7Fever2.0Hereditary0.3Miscellaneous2.5Unknown6.2
In fairly approximate agreement with the returns of the census, are the records of the special schools for the deaf in respect to the causes of deafness in their pupils, with information also as to the amount from the minor diseases. The following table will give the causes by specific diseases, as found in one school, the Pennsylvania Institution, for two years:[21]
CAUSES OF DEAFNESS OF PUPILS IN PENNSYLVANIA INSTITUTION
19061907Per CentPer CentTotal number510100.0500100.0Born deaf21341.820641.2Scarlet fever438.2479.4Meningitis367.1408.0Falls244.7255.0Diseases of ear and throat132.6234.6Catarrh and colds132.6——Measles183.5183.6Brain fever173.3163.2Convulsions142.8132.6Abscesses102.0122.4La grippe102.071.4Accidents (not stated)91.871.4Whooping cough71.471.4Typhoid fever71.461.2Diphtheria61.261.2Mumps51.051.0Paralysis51.040.8Marasmus20.440.8Pneumonia40.820.4Dentition——20.4Dropsy of blood20.4——Chicken pox10.210.2Poisoning10.210.2Intermittent fever10.210.2Blood clotting on brain10.2——Cholera infantum10.2——Gastric fever——10.2Sickness (not stated)102.081.6Unknown377.3387.6
In respect to present activities for the prevention of adventitious deafness, we find the situation very much like that of marking time. Deafness, since the beginning of time, has largely been accepted as the portion of a certain fraction of the race, and any serious and determined effortsfor its eradication have been considered for the most part as of little hope.[22]With the auditory organs so securely hidden away in the head, entrenched within the protecting temporal bone, and with their structure so delicate and complicated, the problem may well have been regarded a baffling one even for the best labor of medicine and surgery. Hence it is that after deafness has once effected lodgment in the system, a cure has not usually been regarded as within reach, though for certain individual cases there may be medical examination and treatment, with attempts made at relief. For deafness in general, it has been felt that there has been little that could be done in the way of prevention or cure beyond the preservation of the general health and the warding off of diseases that might cause loss of hearing.
As a matter of fact, however, altogether too little attention has been given hitherto to the possibilities of the prevention of deafness. Without question there is much at the outset that can be accomplished towards the prevention of those diseases that cause deafness. A large part, perhaps fully a third, as we have seen, are due toinfectious diseases, and it is probably here that measures are likely to be most efficacious. A considerable portion likewise are the result of diseases affecting the passages of the nose and throat, and help should be possible for many of these if taken in hand soon enough. In certain diseases also, as scarlet fever, measles, typhoid fever, diphtheria, and others, there are not a few cases which, so far as deafness as a development is concerned, would prove amenable to skillful and persistent treatment. At the same time due attention to primary ear troubles would in a number of instances keep off permanent deafness. Indeed, it is possible that some thirty or forty per cent of adventitious deafness is preventable by present known means.[23]
Aside from direct medical treatment for those diseases that cause deafness, there are other measures available in a program for the prevention of deafness. One of the foremost essentials is the report to the health authorities of all serious diseases that are liable to result in deafness. In this way proper medical care may be secured, and due precautions may be taken to isolate infectious cases. Even with meningitis, which is so hard usually to deal with and which isso severe in its ravages, there is often some concomitant trouble, and if made notifiable in all cases deafness from it might be checked in no inconsiderable measure. The report of births is also especially needed, and as it becomes obligatory in general, with the consequent detection of physical ailments or disabilities, early cases of deafness may come increasingly to notice, and timely treatment may be availed of. Particular attention is likewise necessary in respect to the medical examination of school children. The proportion of such children with impaired hearing is not slight, even though no great part of them become totally deaf. A committee on defective eyes and ears of school children of the National Educational Association in 1903 found that of 57,072 children examined in seven cities, 2,067, or 3.6 per cent, were extremely defective in hearing.[24]An investigation of the school children in New York City has disclosed the fact that one per cent have seriously defective hearing.[25]Under proper and adequate medical inspection of schools, not only would the need of treatment for adenoids and similar troubles be brought to light, with the result that a number of incipient cases might be stopped in time, but in some instances of deafness alreadyacquired beneficial treatment might be possible.[26]
There is thus a considerable sphere for action towards the prevention of adventitious deafness both by legislation and by education. For the ultimate solution of its problems, however, we have to look mainly to the medical profession. In recent years medical science has won some great triumphs, and in the field of the prevention of deafness no little may be in store to be accomplished in the years to come.[27]Even now, with more particular attention to the diseases of children, and with stronger insistence upon general sanitary measures, the probabilities are that there is less deafness from certain diseases than formerly—a matter which we are soon to consider.
Though as yet there has been little direct action for the prevention of adventitious deafness, there is an increasing concern in the matter, and in this there is promise. By medical bodies in particular is greater attention being given to the subject,[28]and in the widening recognitionof their part as guardians of the public health it may be possible for them to do much for the enlightenment of the public. In one state legislative action has been taken expressly for the protection of the hearing of school children. This is Massachusetts, which requires the examination of the eyes and ears of the school children in every town and city, the state board of education furnishing the tests.[29]In some states also general inspection of schools is mandatory by statute, and in others permissive, while in several there are local ordinances with the force of a state law.
In combating adventitious deafness, then, our attack is to be directed in the largest part upon those diseases, especially infantile and infectious diseases, that cause deafness; and it is upon the checking of their spread that our main efforts for the present have to be concentrated. At the same time the better safe-guarding of the general health of the community will insure a proportionate diminution of deafness. Beyond this, we will have to wait upon the developments of medical science, both in the study of the prevention of diseases and of their treatment; and can trust only to what it may offer.[30]
Our main interest in the problem of adventitious deafness lies in the possible discovery whether or not it is relatively increasing or decreasing among the population, and in what respects signs appear of a diminution. We have just seen the likelihood of a decrease from certain causes; but we are to find what is indicated by statistical evidence.
To be considered first is adventitious deafness as a whole. Respecting it our only statistics are in the returns of the censuses since 1880, the different forms of deafness not being distinguished before this time. The following table will show the number of the adventitiously deaf as reported by the censuses of 1880, 1890 and 1900, with their respective percentages and ratios per million of population.[31]
NUMBER OF THE ADVENTITIOUSLY DEAF IN 1880, 1890 AND 1900
TotalNumberAdventitiouslyDeafPercentageRatio perMillion ofPopulation188033,87810,18730.120.3189040,56216,76741.126.8190037,42618,16448.423.9
From this it appears that adventitious deafness is increasing in relation to total deafness, which is most likely the case, as congenital deafness, as we shall see, is evidently decreasing. Whether or not adventitious deafness is increasing in respect to the general population, the table does not disclose definitely. The statistics probably are not full enough to afford any real indication yet.
Our next inquiry is in respect to the increase or decrease of adventitious deafness from the several diseases individually, which is, upon the whole, the more satisfactory test. Here also, unfortunately, our statistics are very limited, and our findings will have to fall much short of what could be desired.
The following table, based on the returns of the censuses of 1880, 1890 and 1900, so far as the approximate identity of the several diseases can be established, will give the respective percentages found.[32]
CAUSES OF ADVENTITIOUS DEAFNESS IN 1880, 1890 AND 1900
188018901900Scarlet fever7.911.811.1Meningitis8.47.89.6Catarrh and catarrhal fevers0.93.33.6[33]Diphtheria0.20.5—[34]Abscess and inflammation1.02.5—[35]Measles1.32.52.5Whooping cough0.50.8—[34]Malarial and typhoid fevers1.71.83.6Other fevers1.1—2.0
In this table the most noticeable thing is perhaps the persistency with which we find most of the diseases to recur, with apparently no great change, while in certain ones, as catarrh and malarial and typhoid fevers, there seems to be rather an increase. It would be best, however, not to place very great confidence in these figures, but, so far as the census reports are concerned, to wait for more precise and uniform statistics.
We have, further, the statistics published in the reports of certain schools for the deaf. While these are perhaps not of sufficient extent to warrant full conclusions, they may be regarded as quite representative;[36]and though to be taken with something of the caution as the census figures, they may serve to throw some light uponthe situation. Comparison of the proportions of pupils deaf from the several diseases at different times may be made in two ways: by finding the respective proportions over a series of successive years from a certain time back down to the present, and by contrasting the proportions in two widely separated periods, one in the present and one in the past. These will be taken up in order.
The following tables give the percentages of cases of deafness in pupils from the important diseases as found in six schools in successive years: in the New York Institution in the total annual attendance from 1899 to 1912; in the Michigan School in the total biennial attendance from 1883 to 1912; in the Pennsylvania Institution in the number of new pupils admitted quadriennially from 1843 to 1912; in the Western Pennsylvania Institution in the number admitted biennially from 1887 to 1912; in the Maryland School in the number admitted biennially from 1884 to 1911; and in the Wisconsin School in the number admitted biennially from 1880 to 1908.
I. CAUSES OF DEAFNESS IN NEW YORK INSTITUTION FROM 1899 TO 1912
18991900190119021903190419051906190719081909191019111912Total Number466476481477464503508510543555565570546518Congenital36.027.126.840.936.241.146.231.833.334.434.932.834.636.6Scarlet Fever11.410.18.97.16.56.96.54.95.35.05.76.15.75.0Meningitis9.59.47.77.97.87.911.012.216.818.617.717.919.019.7Brain Trouble10.19.28.38.17.25.95.97.19.08.38.78.38.08.9Falls9.07.25.44.53.94.23.85.25.96.16.05.15.55.6Measles5.13.83.82.13.94.54.14.14.84.74.44.60.20.7Typhoid Fever3.72.31.61.00.91.21.01.01.31.31.21.10.90.5Convulsions3.24.43.22.92.60.21.81.81.91.51.91.92.02.1Various Fevers2.51.51.41.01.71.61.61.61.51.30.70.50.50.7Catarrh2.32.11.91.81.61.21.02.01.91.91.40.81.00.5Diphtheria1.91.71.91.00.90.40.60.80.90.90.70.70.70.5Pneumonia1.50.80.80.61.10.21.01.11.10.91.11.10.70.5Whooping Cough1.7—1.61.21.11.00.80.60.90.90.50.50.50.2Miscellaneous and Unknown2.120.426.719.818.623.714.725.915.414.215.118.620.718.5
II. CAUSES OF DEAFNESS IN MICHIGAN SCHOOL FROM 1883 TO 1912
188318841885188618871888188918901891189218931894189518961897189818991900190119021903190419051906190719081909191019111912Total Number302336342350343365428412441447451404361354353Congenital7.018.823.126.324.226.325.230.328.831.532.836.635.735.031.2Meningitis28.828.123.123.121.315.815.614.510.29.24.68.69.58.88.2Scarlet Fever12.211.812.311.29.09.69.59.79.59.37.66.95.83.64.5Brain Fever6.26.54.83.75.26.96.66.35.43.83.82.72.52.31.0Typhoid Fever4.63.64.14.34.71.91.81.42.52.21.31.01.41.51.7Measles3.64.13.92.92.61.40.81.93.23.12.92.94.13.43.1Diphtheria0.6——0.30.30.30.20.20.40.20.40.50.20.30.3Catarrh0.60.60.90.80.91.11.9—2.93.53.32.81.92.50.8Various Fevers2.91.52.02.63.04.44.41.72.92.93.32.50.52.01.4Whooping Cough1.31.21.51.51.53.03.83.62.72.53.13.44.44.85.1Pneumonia————————0.20.20.4—0.70.60.8La grippe————————0.91.11.61.53.02.3—Miscellaneous and Unknown32.223.824.323.327.329.330.230.430.431.534.930.630.332.941.9
III. CAUSES OF DEAFNESS IN PENNSYLVANIA INSTITUTION FROM 1843 TO 1912
184318461847185018511854185518581859186218631866186718701871187418751878187918821883188618871890189118941895189818991902190319061907191019111912Total Number90111125143167152150178282233261207248250239240282152Congenital54.458.556.046.853.348.440.042.131.224.434.147.346.841.632.235.833.734.2Scarlet Fever13.318.012.816.89.619.716.018.618.113.714.914.014.111.26.310.43.95.2Meningitis——0.8——2.01.39.618.125.716.45.85.67.68.47.117.415.1Measles1.12.71.62.82.43.34.01.11.72.61.93.93.24.44.64.53.53.9Whooping Cough2.20.90.80.71.20.71.30.60.30.8—0.50.40.81.70.72.91.3Catarrh—0.9————0.70.62.1——3.94.86.84.21.22.51.3Brain Fever——2.82.1—6.04.7———0.82.95.24.03.41.72.92.6Typhoid Fever———1.40.60.72.62.72.12.63.42.93.6—2.50.73.91.3Diphtheria——————0.7————0.51.62.00.82.51.22.0Pneumonia———————————0.5——0.80.41.24.8La grippe————————————0.4—2.11.20.3—Mis. and Unknown29.019.225.229.432.919.228.724.726.330.228.517.814.321.633.033.826.628.3
IV. CAUSES OF DEAFNESS IN WESTERN PENNSYLVANIA INSTITUTION FROM 1887 TO 1912