Abstract
We mailed questionnaires to 98 university hospitals and 939 hospitals with 200 beds or more throughout Japan asking for information on patients treated for sensorineural hearing loss between January 1 and December 31, 1987. The number of patients treated for sensorineural hearing loss in 1987 in Japan was estimated as follows: i) sudden deafness in 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss in 800-2,000, iii) perilymphatic fistula in 200-310, iv) mumps deafness in 200-400, and v) unilateral profound deafness in 2,000-3,000. Sex ratio (men over women) was 0.9 in sudden deafness and mumps deafness, 1.1 in idiopathic bilateral progressive sensorineural hearing loss and 1.5 in perilymphatic fistula. Patients were distributed with a definite peak from 50 to 59 years old in sudden deafness, from 30 to 39 years old in perilymphatic fistula, and two apparent peaks in teenagers and those aged 60-69 years in idiopathic bilateral progressive sensorineural hearing loss.