ABR slow wave and stimulus duration.
The slow wave (SW) component of the auditory brainstem response (ABR) was recorded in eight young adult subjects of both genders who had normal hearing sensitivity and who exhibited normal behavioral temporal integration (TI) functions. Test stimuli were 500- and 2000-Hz tone bursts, with rise and decay ramps of two periods, ranging in total duration from 2.5 msec to 44 msec. The responses appeared to be made up of contributions from both SW and wave V of the ABR. These composite waveforms showed a progressive, systematic, and statistically significant increase in peak amplitude and latency as a function of stimulus duration at 2000 Hz, but not at 500 Hz. Some pros and cons of recording the SW component during ABR audiometry are discussed, along with other advantageous properties of ABR SW. Additional approaches that may lead to the enhancement of the detectability of short-latency auditory evoked responses are noted.