Auditory image movement in evoked potentials

Long-latency auditory evoked potentials (AEPs) were tested in subjects following binaural stimulation with click trains with gradually changing interaural time delays (delta Ts). With appropriate change of the delta Ts this sound signal could produce the sensation of a moving fused auditory image (FI). It was found that the N1-P2 complex of the AEPs rose in amplitude with the increase of the click rate above 15 Hz, and to a greater extent for the moving than for the unmoved FIs. Binaural release from masking (as measured by the binaural masking level difference (BMLD) for the AEPs) amounted to 6 dB for the unmoved FI. For the moving FI the BMLD for the AEPs amounted to 2.8 and 3.5 dB in men and 13.4 and 11.3 dB in women, for the left and right hemispheres respectively. The amplitude of the N1-P2 complex following stimulation with the 'moving' and 'unmoved' sounds was larger in women than in men.