BINAURAL INTERACTION IN THE AUDITORY BRAIN-STEM RESPONSE - MULTICHANNEL RECORDINGS

Binaural interaction (BI) waveforms were derived from multichannel rec ordings of auditory-evoked brainstem responses obtained at moderate an d high intensity levels. The component latencies of all the BI respons es derived from the contralateral channel were significantly prolonged compared with those derived from ipsilateral and non-cephalic channel s. These channel differences were identified only at the moderate inte nsity level, indicating that BI cannot be isolated from the effects of stimulus interaction at higher intensities. The amplitudes were not s ignificantly 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 simultaneo us multichannel recordings may provide an index of true neural interac tion.