Interaction of click intensity and cochlear hearing loss on auditory brain stem response wave V latency.

Auditory brain stem responses (ABRs) to 95, 80, 60, 40, and 30 dB nHL clicks were retrospectively studied from 103 patients (194 ears) with various degrees of cochlear impairment. Hearing loss and sample size were balanced across gender. Results indicate that the slope of the wave V latency versus 4000 Hz hearing loss function doubles as click intensity is decreased from 80 (0.01 msec/dB HL) to 60 nHL (0.02 msec/dB HL). Overall results indicate a slope increase of 0.0004 msec for each decibel decrease in click intensity from 95 to 30 dB nHL. Intersubject variability increased with increased hearing loss and/or decreased stimulus intensity. The effects of hearing loss on wave V latency are minimal, and intersubject variability is less if high-intensity clicks (greater than or equal to 95 dB nHL) are used. No differences in the effects of hearing loss on wave V latency were seen between males and females. Latency corrections for cochlear hearing loss should, therefore, consider stimulus intensity.