AN EXPERIMENTAL STUDY OF AUDITORY FATIGUE
MORIKATSU YAMAZAKI · Nippon Jibiinkoka Gakkai Kaiho · 1966
Following the exposure to pure tone (500cps)for one minute with various degrees of intensity, Temporary Threshold Shift (T.T.S.) observed in humans was measured by the use of Békésy audiometer. The results obtained are as follows:1) When Istimulation tones were weaker than 20db above sensation level, the maximum T.T.S.values appeared at the same cycle with the stimulation tone, and T.T.S. was distributed symmetrically on the lower and higher frequency ranges.When 40 and 60db above sensation levels were given as the stimuli, the maximum T.T.S. values were located at the same cycle, but the symmetri.cal distribution of T.T.S. was lost and they moved towords the higher frequency ranges more widely.When 80 and 100db above sensation level were given as stimuli, the muximum T.T.S. values moved to only 1/5 octave higher frequency range.from the stimulation tone.2) When the stimulation tone and the test tone were the same, the T.T.S. values did not always rise ie proportion to the intensity of stimulation tone.