Efferent Inhibition of Auditory-Nerve Responses: Dependence on Acoustic-Stimulus Parameters

Abstract

Electrical stimulation of the crossed olivocochlear bundle in anesthetized cats reduces auditory-nerve responses (N1) if the acoustic stimuli are at low sound-pressure levels but does not produce detectable changes in neural responses for click stimuli more than 60 to 70 dB above visual-detection level for N1. When the sound-pressure levels of high-frequency (10 000-Hz) and low frequency (400-Hz) transient acoustic stimuli were matched according to a physiological criterion, the neural response to the high- frequency stimulus was reduced more by olivocochlear bundle stimulation than the response to the low-frequency stimulus. These result, suggest certain characteristics for the mechanisms which influence the activity of single auditory-nerve fibers.