Auditory evoked potentials in the Japanese monkey.

Auditory sensitivity based on auditory brain stem response (ABR), whole nerve action potential (AP), and cochlear microphonics (CM) to tone bursts of 0.5-8 kHz were compared with behavioral audiometry in the Japanese monkeys. Although sensitivity loss at 4-6 kHz was observed in these potentials, an increase in sensitivity at 8 kHz was obtained only in the ABR. Thus the sensitivity loss at 4-6 kHz originates at the peripheral system and the increased sensitivity at 8 kHz originates at the central.