The Present Condition of the Persons with Hearing Loss, Treated as the Physically Handicapped in Tochigi Prefecture

Abstract

Statistical observations of the 5049 persons with severe hearing loss of over 60dB in conversational area from 1951 to 1968 in Tochigi Prefecture were made. They were classified as follows; deafness including deafmúte: 1849 cases (37%), perceptive deafness: 1626 cases (32%), mixed-type deafness: 1392 (28%), and others: 172 cases (3.4%).
90% of perceptive deafness had unknown etiology, while more than 82% of mixed-type deafness were related to chronic otitis media.
The occurrence of congenital deafness has not been changed during the past 40 years. In the cases of congenital deafness, the consanguineous marriage was found higher than in those of the acquired deafness. These tendency was also suggested in the regional distribution of the occurrence of the deaf. In the former the familial occurrence of deafness and/or severe hearing loss was also higher than in the latter.
Severe hearing loss due to chronic otitis media has been decreased rapidly with the development of antibiotics.
Both perceptive and mixed-type deafness tended to increase in number with the age.
Further investigations on symptoms, onset and progress of deafness, the effect of hearing aid and the presence of tinnitus and vertigo were made in the above-mentioned deafness.
It was suggested by the detailed history taking that it is possible to detect more cases of streptomycin deafness out of the cases of perceptive deafness with unknown etiology.