Auditory Fatigue Produced by Continuous and Interrupted White Noise

Is the temporary hearing loss following exposure to repeated bursts of white noise determined by the long‐time average level or the burst level of the noise? Thresholds of a 4‐kc interrupted tone were obtained for eight subjects before and after two minutes of exposure to the following noise conditions: a noninterrupted noise at 120 db SPL and also at 110 db SPL, and interrupted noises with a burst level of 120 db SPL and with “on” and “off” durations of 1 and 9, 10 and 90, 100 and 900, and 1000 and 9000 milliseconds, respectively. The long‐time average level of the interrupted noises thus was 110 db. Results indicate that the shifts in threshold did not differ greatly among the various interrupted noises. The average amount of fatigue produced by the interrupted noise was closer to that produced by the noninterrupted noise at 110 db than that produced by the noninterrupted noise at 120 db. Therefore, within the conditions examined, the fatigue produced by an interrupted noise is more nearly determined by the long‐time average level than by the burst level.