Effects of stimulus repetition rate on the auditory brain stem responses (ABR).

Brain stem auditory evoked potentials were recorded from 26 normal subjects who listened to 100 ms clicks at 10, 20, 50, and 100 repetitions per second at varying intensities. A 0.5+/-0.3 ms shift of the V wave latency was observed between 10 clicks per second and 100 clicks per second; a lesser difference was found when the repetition rate was shifted between 10 to 50, 20 to 50, or 20 to 100 clicks per second. No significant differences were observed when the repetition rate moved from 10 to 20 or between 50 and 100 clicks per second. Whatever latency shifts were observed appeared to be independent of the stimulus intensity. Waveform morphology seemed to be the same between 10 and 20 clicks per second, with only minor changes observed at the 50 clicks per second rate. At 100 clicks per second a decrease or a complete disappearance of some components or both was seen. These changes are accounted for by peripheral phenomena for the most part, and a number of clinical applications are suggested based on these observations.