Abstract
Effects of homo-phasic and anti-phasic stimulation on the binaurally evoked auditory brain-stem responses (ABRs) were investigated in 10 normal subjects. Clicks were presented at 47 dB SL with two in-phase (binaural condensation and binaural rarefaction) and two out-of-phase (left ear condensation, right ear rarefaction and right ear condensation, left ear rarefaction) stimulus configurations. The earlier of the latencies obtained with homo-phasic stimulation were compared with the earlier of the latencies obtained with anti-phasic stimulation. Repeated measures ANOVAs on the peaks (P) and toughs (N) of each component, revealed significantly earlier latencies for the anti-phasic condition, for components IIN (p<0.049). IIIP (p<0.012) and VIN (p<0.025). Similar trends were apparent for components IVP (p<0.075). VP (p<0.099) and VIP (p<0.12). The results are discussed in terms of the binaural-level difference phenomenon and possible clinical applications.