1992 Volume 35 Issue 3 Pages 246-252
The purpose of this study is to analyze hearing impairment in primary school children in Sendai City from 1968 through 1987.
The following results were obtained:
1) The prevalence of hearing impaired children had rapidly decreased yearly from a peak of 1.94% in 1972 and was 0.6-0.7% since 1983. The cause of this reduction was mainly due to the decrease of a conductive hearing loss.
2) Hearing loss was more predominant in boys (60%). Sensorineural and conductive hearing losses were also more frequently among boys.
3) Unilateral hearing loss was found more common than bilateral hearing loss.
4) The prevalence of a hearing loss due to secretory otitis media had decreased, although it still accounts for approximately 60% of a conductive hearing loss and 30% of all cases with hearing impairment.
5) The prevalence of impaired hearing caused by chronic otitis media had been constantly decreased to 0.02% in 1985.
