Abstract
418 workers who were exposed to noisy environment in industry were examined by an usual audiometer. The following results were obtained.
1) There are pretty many middle-aged person in industry workers who were exposed to noisy environment.
2) The most of test ears showed the hearing loss from 5 to 25 db, but about a tenth of these showed the hearing loss above 30 db.
3) The difference of about 5 db was observed between the hearing loss of boss test ears, and its standard deviation was 8. 16db.
4) The appearance of the subjects whose hearing loss were above 30 db increased due to working years above 10 years.
5) The hearing loss in the high frequency range was appeared in the early stage of working years, and the one in the low frequency range was appeared in the late stage.
