Localization of Moving Sound Stimuli under Conditions of Spatial Masking

Abstract

The aim of this study was to investigate spatial masking of noise signals in the delayed motion paradigm. Spatial effects were created by interaural level differences (ILD). Stationary maskers were located laterally or near the head midline, while test signals moved at different velocities from the head midline towards the ears, or in the opposite direction. The masking effect was measured by shifts in the perceived azimuthal positions of the starting and final points of signal trajectories, compared to their positions in silence. The perceived trajectories of all test signals shifted in the opposite direction from the masker. The masking effect was most pronounced in the spatial regions closest to the maskers, and was stronger when the signal moved towards the masker, compared to moving away from it. The final points were perceptually shifted further than the starting points. Signal velocity and masker presentation side (left or right) did not change the degree of masking.