SN10 auditory evoked potential revisited

The slow brainstem response (SN10) was originally described as a slow negative wave occurring at a latency of 10 msec post stimulus onset. In the late 1970s and early 1980s it was considered to be promising for estimating hearing thresholds at low frequencies. However, there have been controversies regarding waveform description, recording stimulus parameters, and factors affecting the response. Consequently, the SN10 has not become a popular clinical test for estimating hearing thresholds electrophysiologically. However, recent observation of ABR waveforms using low-frequency stimuli and broad-band filtering indicate that the negative wave after wave V can be highly identifiable. This wave in many instances is the SN10. Therefore, this article was designed to review various aspects of the SN10 to make clinicians more aware of its possible applications in estimating low-frequency hearing thresholds.