騷音下従業員（正常聴力者）の騒音負荷試験

　I．緒言

　職業に従事する者の健康管理が徹底するにつれて強大騒音による聴器障害が問題にされ，その対策ならびに障害の予防について研究が行われている。

　障害の予防に当つては音源への対策は勿論であるが，これについてはなかなか容易ではない。

A suggestive factor by which hard of hea-ring may be circumbented among workers exposed to noise is found.

Two groups of persons, one in whom there were no effect of hearing working under occu-pational noise for a considerable period time and the other, who were normal in hearing and were not exposed to noises : there two groups were exposed alike to thermal noise. Their respective rate of recovery were com-pared. The recovery in the first group was quite short in time : the transient loss of hearing among them was aparently small in degree.