Effect of Auditory Fatigue on Differential Intensity Thresholds

Although the great majority of studies on auditory fatigue have utilized the TTS (temporary threshold shift) as the primary index of fatigue, it also manifests itself in many other ways. Several studies have reported the existence of recruiting in the fatigued ear —as demonstrated at suprathreshold intensities by the use of loudness balance tests, and at threshold intensities by a decrease in the size of the recording attenuator pen excursions when the absolute threshold recovery curve is traced. This paper is a report of the change in the size of the intensity dl's following fatigue. Two parameters have been investigated, viz., the severity of the fatigue as defined by the TTS at the time of the dl determinations, and the sensation level (post stimulation) of the test tone. Both of these factors are found to be related to the change in the dl's.