Abstract
The author reported the results of the auditory fatigue test for the students who had been working for the instructive purpose in noise circumstances.
He tested the 280 ears of the boys, 15-18 years old, who had been working about three and a half hours a day in the noise of 60-100 db.
The catheterization test, the air and bone conduction test, the blocked bone conduction test and the simplified auditory fatigue test newly deviced by the author were employed.
In the auditory fatigue test, the stimulating tone (2 kc, 90 db) was given for 2 minutes to cause auditory fatigue whose recovery course was examined with the test tones of 2 kc and 3 kc respectively.
The number of boys who showed abnormal auditory fatigue through the test tone of 2 kc increased in accordance with the length of working time: 5.3% of the boys who had been working since 3 months before, 20.9% of those who had been working for 9 months, and 27.1% of those who had been working for 1-3 years. The number of the boys who showed abnormal auditory fatigue through the test tone of 3 kc increased in the same way 5.3%, 16.3% and 27.1% respectively.
It was concluded that when the youth of 15 -18 years worked in the noise of 60-100 db for 3.5 hours a day, the number of the boy who showed abnormal auditory fatigue increased by more than 10% after 10 month working and increased by more than 21% after 1-3 year working.
