Human auditory nerve action potentials and brain stem evoked responses.
Latency-intensity (L-i) functions for (1) the auditory nerve action potential (AP) N1 peak, (2) the brain stem evoked response (BER) V peak, and (3) the N1-V interval were related to hearing level and lesion location. The AP L-l curves tended to steepen with increasing 4 to 8 kHz hearing level. This relationship was identical for cochlear and retrocochlear ears, except for a few retrocochlear ears with "inappropriate AP perservation." Both high-frequency cochlear loss and retrocochlear abnormality prolonged peak V latency, but retrocochlear abnormality generally prolonged it more. Among cochlear-loss ears, as 4 to 8 kHz hearing levels increased, N1-V intervals decreased and L-i curve slopes increased. In contrast, retrocochlear abnormality greatly prolonged N1-V intervals. As a retrocochlear sign, N1-V prolongation was slightly more reliable than V prolongation.
D000200:Action Potentials; D001932:Brain Neoplasms / Q000175:diagnosis; D001933:Brain Stem / Q000502:physiology; D003056:Cochlear Nerve / Q000502:physiology* / Q000503:physiopathology; D003390:Cranial Nerve Neoplasms / Q000175:diagnosis / Q000503:physiopathology; D005071:Evoked Potentials; D006309:Hearing / Q000502:physiology*; D006801:Humans; D009442:Neurilemmoma / Q000175:diagnosis / Q000503:physiopathology