Abstract
The variation in the auditory acuity in the normal ear has been studied only by a small number of authors except on the rise in the audible threshold of a high pitched tone in old people. The auther has studied the effect produced by different physiological conditions on the hearing acuity of an individual.
The author made 76 young people, aged 17-21, play 9 kinds of games, tennis, judo, Japanese fencing, volleyball, basketball, 1500 meter race, Rugby, wrestling and 5000 meter race. Immediately before, immediately after, 30 minutes after, 1hour after and 2 hours after the exercises, the author made the pure tone audiometry and examined the variation in the auditory acuity in 152 ears.
The hearing loss after the exercises was most strongly observable in the sound of 4096 cps. The restoration of the hearing loss took 30 minutes with tennis, judo, Japanese fencing, and 1 hour with volleyball, basketball, 1500meter race, rugby, and 2 hours with wrestling, 5000meter race (in this case excepting a few ears).
C5 dip was observable in no ear with tennis, judo ; in 3 among 18 ears with Japanese fencing in 3 among 12 ears with volleyball; in 4 among 16 ears with basketball; in 4 among 20 ears with 1500 meter race; in 5 among 18 ears with Rugby ; in 10 among 24 ears with wrestling; in 12 am ong 20 ears with 5000meter race. The appearance of the dip became more frequent and its depth greater in proportion to the severeness of the exercises and the degree of the fatigues.
The author compared this temporary appearance of the c5 dip after physical exercises with that of auditory fatigue, and deduced the cause of this phenomenon as the result of circulatory disturbance.
