Brainstem response (ABR) to rarefaction and condensation clicks in normal hearing and steep high-frequency hearing loss.

ABR in response to 2.0 kHz haversine waves was obtained in normal-hearing subjects and in 27 ears with steep high frequency hearing loss. Rarefanction (R) clicks had a significantly shorter latency to wave V than condensation (C) clicks (mean = 0.13 ms SD = 0.16 ms, p less than 0.001). This value corresponds to a frequency of generation of ABR of 3-4 kHz. The latency difference between R and C clicks increased in reversed proportion to the cut-off frequency of the pure tone audiogram in the ears with steep high-frequency hearing loss. It was concluded that R-C latency difference can be used as an approximate indication of frequency of generation of ABR.