[Motion-Onset Responses During Active and Passive Listening to the Moving Sound Stimuli]

This study investigated the energy-onset and motion-onset responses (N1, P2, cN 1 and cP2 components of the auditory evoked potential) elicited by moving sound stimuli in the passive and active listening conditions. In the passive conditions the subjects were distracted from auditory information; in active conditions they lo- calized the starting and final points of the stimulus trajectory. The sound movement to the left/right from the head midline was produced by linear-changes of the interaural time delay (ITD). The onset of motion was preceded by stationary sound located near the head midline. In the active conditions, the NI component was higher and the P2 component was higher and peaked later as compared to the passive listening. The early and later parts of the motion-onset response (cN 1 and cP2) also were larger in magnitude and peaked later during active listening. Both in active and passive conditions, cNI and cP2 amplitude exhibited increase and latency showed decrease when the stimulus velocity increased. Contralateral asymmetry was found only in the mo- tion-onset responses recorded from the left hemisphere.