A lower audiometric limit for auditory brainstem response (ABR).

A lower audiometric frequency limit for reproducible ABR in response to 75 dB and 85 dB nHL 2.0 kHz haversine wave stimuli was defined by testing subjects with steep high-tone loss of varying cut-off frequencies. The limit between audiograms with and without reproducible ABR passed roughly through 40-50 dB HL at 500 Hz and 80-90 dB HL at 1000 Hz. Lack of ABR was not equivalent to lack of potentially useful hearing.