徹夜麻雀の健耳聴力に及ぼす影響について

　序言

　音響性外傷を主としたC⁵ dipに関する研究は近年，各種中毒，頭部外傷，スポーツ後等にも出現する事が認められているが，余等は身心共に極度に疲労すると思われる徹夜麻雀時に於ける聴力を時間の推移と共に検査し，聊か興味ある知見を得たので茲に報告し，諸賢の御批判を乞わんとする次第である。

　The effect that "all-night games" might have on the hearing acuity of a person is studied by selecting at random volunteers, normal in health and hearing, who were requested to play an all-night game of majong. Audiograms, both air and bone conduction, showed a dip only at 4000 cps, which were alike in both cases at 0200 and 0400 hours, This fact appeared to be more prevalent particularly among those who were sympthomimetic in type. By apparent close similarity between this change and that of flicker during normal mental excercise the authors believe that the cause of C⁵ dip may be central in origin.