Influence of the stimulus repetition rate on brain-stem-evoked responses in man

In order to record brain-stem-evoked responses as fast as possible, the influence of the stimulus repetition rate was investigated. The repetition frequency was varied from 2.5 to 80 Hz. The amplitudes of N2-N4 diminish uniformly with increasing stimulus rate. The repetition rate has little or no influence on the amplitude of N5; however, increasing the repetition frequency about 10 Hz causes an increase in the latencies of N2-N5. It seems that the decrease in the amplitude of N2-N4 and the increase in the latencies of N2-N5 are of cochlear origin, since the amplitude and the latency of the cochlear responses are influenced in the same way by the repetition rate as the above-mentioned brain stem responses.