Motion onset responses elicited by sound stimuli with interaural level differences

We studied the evoked responses of the human brain elicited by the onset of sound motion (motion-onset response, MOR). Sound motion was created by means of linear changes in the interaural level differences (ILD). The structure of the ILD-related MOR was similar to that reported in the studies which used changes in the interaural time delay. The amplitude of the cN1 component increased with sound velocity, regardless of motion direction, and the cP2 deflection increased only in the case of motion from the center to the periphery. The amplitude of both cP1 and cN2 components did not depend on motion velocity. Centrifugal motion evoked a stronger MOR than centripetal motion, which corresponds to the hemifield model of lateralization (i.e. opponent channels model). Our findings suggest that motion direction (towards the center or towards the periphery) was reflected in the MOR potential in a wider time interval than velocity.