Binaural interaction in brainstem potentials of human subjects.

Binaural interaction in the short-latency averaged auditory evoked potentials (AEPs) can be assessed from the binaural difference waveform (BD). The BD is derived by computing the difference between the AEP evoked by simultaneous clicks from both earphones and the sum of two other AEPs: one evoked by clicks from the right earphone alone and the other evoked by clicks from the left earphone alone. Once the contributions of acoustic cross talk and the middle ear reflex are eliminated, the BD can be considered to represent neural binaural interaction. This interaction begins after wave III and has its first major peak during the dowmslope of wave V. The more localizing value than the AEPs alone since the BD probably represents a subpopulation of generators of the AEPs, which show binaural interaction at the single cell level.