Onset-offset effects of the human brainstem auditory-evoked response

Brainstem auditory-evoked responses (BSAER's) were obtained from 4 normal-hearing young adults to a 2-kc/s tonal stimulus of 2-, 3-, 4-, 5-, 6-, 7- or 8-msec duration at 60 db sensation level. Latency of Jewett Wave V was recorded averaging 4096 sweeps; stimuli had a 1-msec rise-fall time, with a 65-msec interstimulus interval. A Wave V response to the onset transient was present for all durations. For stimulus durations of less than 5 msec no reliable offset response was noted. Latency measures indicated the onset response to be much less variable than the offset response. The onset response latency of Wave V remained stable over a stimulus duration range of 2-8 msec. The BSAER of a single S demonstrated the intrasubject variability of the offset response as a function of stimulus duration.