Short-term auditory deprivation: effect on brainstem electrical response.

Recent research has associated long-standing conductive hearing losses and changes in brainstem neural responses. Investigations on human subjects to date have used behavioral modes in evaluating response changes for both short-term (induced) and long-term conductive losses. The present study measured brainstem electrical responses (BSERs) from 30 normally hearing adults divided into unilateral-induced conductive-loss groups of 10, 20 and 30 h. This auditory deprivation produced a significant decrease in the wave-I latency (auditory nerve response) across all groups. It is concluded that short-term auditory deprivation can result in VIII nerve fiber hyper-excitability when initially stimulated after the deprivation period. The occurrence of temporary changes under very short-term deprivation raises the possibility that alterations to brainstem neural responses may also be measurable electrophysiologically in individuals with long-term conductive losses, such as children with otitis media.