Low-frequency activity in the binaural interaction component of the auditory brain stem response

The purpose of this study were to determine (1) the contribution of low-frequency activity in the auditory brain stem response (ABR) to the binaural interaction component, and (2) an optimal set of parameters for recording the binaural interaction component. ABRs were recorded from 12 adult subjects with normal hearing using 1000 Hz tone pips at three stimulation rates (10, 25, and 50/sec) and two physiological filters (150-3000 and 30-3000 Hz). The latencies of wave V in the sum of the left and right monaural responses [V(L + R)] were shorter with the 150 to 3000 Hz filter than with the 30 to 3000 Hz filter, whereas the amplitudes of V(L + R) and peak A of the binaural interaction component were similar. The amplitudes of V(L + R) and A were larger for 50/sec than for 10 or 25/sec, but the amplitude ratio of peak A to wave V(L + R) was not different. In conclusion, (1) the activity between 30 to 150 Hz did not enhance the binaural interaction component, and (2) the largest and most reliable binaural interaction component was recorded with a rate of 50/sec and a filter setting of 150 to 3000 Hz.