Histological as well as electrophysiological studies on the auditory nerve of monkey revealed that
1. The cochlear nerve bundle is almost free from nerve cells whereas the vestibular nerve has many nerve cells in it.
2. The latency of response on each cochlear nerve fiber in response to sound stimulation was determined by measuring the time interval between the arrival of sound at the ear and the beginning of nerve fiber discharge recorded at the intracranial cochlear nerve bundle. It was very short, between 1.0 and 2.0 msec. when the CF of the neuron was higher than 100°cps. while it was rather long, longer than 2 msec. when the CF of the neuron was lower than 1000cps.
3. There was no discrepancy between the conclusion obtained from the electrophysiological studies on the cochlear nerve fibers and that obtained by the histological studies on the cochlear nerve.