Effect on Auditory Functioning of Repeated Exposure to Temporary Fatigue

Abstract

The experiments reported assess (1) the effect of repeated high-intensity stimulation on the threshold of audition and on intensity discrimination and (2) the effect of recovery time on intensity discrimination, holding degree of TTS constant. The first experiment exposed Ss to a 2-Kc-sec tone presented at 105 dB SL for 2 min. Pre- and post-exposure measurements of the threshold of audition and intensity discrimination were obtained for 20 sessions. The second experiment varied the duration and level of the high-intensity fatiguing stimulus so that a given TTS (10 or 20 dB) could be obtained at a specific time period after exposure. Pre- and post-measurements of intensity discrimination were obtained. The results showed a trend, possibly indicative of learning, toward a lower pre- and post-exposure threshold—but this trend was not supported statistically. Consequently, it can be concluded that repeated high-intensity stimulation similar to that in the experiment did not result in any systematic shift in sensitivity. Additionally, it appears that the degree of TTS is the determiner of any change that occurs in intensity discrimination, rather than the time of recovery at which the measurement is obtained.