Auditory Sensitization

Abstract

This experiment studied the lowering of the absolute auditory threshold that follows low-tone stimulation. Monaural thresholds were determined continuously with a recording audiometer before and after the ear was exposed to a pure tone. The frequency, intensity, and duration of both the exposure tones and the test tones were varied. Auditory sensitization was found to be a general effect among seventeen subjects. The magnitude of the effect was investigated intensively with three subjects. Their results demonstrated that sensitization produced by a pure tone is nonspecific: a given tone can sensitize the auditory system to a relatively wide range of test frequencies. Conversely, a relatively wide range of exposure frequencies can sensitize the auditory system to a given test tone. This nonspecificity is consistent with what we know, through microelectrode studies, about the spread of energy on the basilar membrane and the spread of excitation in the auditory nervous system. Contralateral sensitization effects were found.