Binaural interaction in the auditory brainstem response. Multichannel recordings.

Binaural interaction (BI) waveforms were derived from multichannel recordings of auditory-evoked brainstem responses obtained at moderate and high intensity levels. The component latencies of all the BI responses derived from the contralateral channel were significantly prolonged compared with those derived from ipsilateral and non-cephalic channels. These channel differences were identified only at the moderate intensity level, indicating that BI cannot be isolated from the effects of stimulus interaction at higher intensities. The amplitudes were not significantly different across channels or intensities, indicating that ipsilateral, contralateral or non-cephalic recordings can be used to study BI. However, identification of channel differences on simultaneous multi-channel recordings may provide an index of true neural interaction.