The binaural interaction component in human ABR is stable within the 0- to 1-ms range of interaural time differences

The effect of unilaterally delayed acoustic stimuli on binaural interaction was studied in 12 subjects with normal hearing. Auditory brainstem response (ABR) was obtained in the midline between the forehead and the neck, and click stimuli were unilaterally delayed at 0.2-ms intervals in the 0- to 1-ms range. Binaural interaction was evaluated by measuring the beta wave in the binaural difference waveform, i.e. the remainder after subtracting the binaurally evoked registration from the sum of the two monaural registrations. Computation of the binaural difference waveform showed the beta wave amplitude to be relatively stable throughout the 0- to 1-ms range of interaural time differences. This finding suggests stable binaural interaction within the range of interaural time differences where binaural click stimuli induce a binaurally fused intracranial image.