Localization of Correlated and Uncorrelated Audio Signals in the Horizontal Plane under Masking Conditions

The effect of the masker on the localization of the signal was investigated in the free field conditions. Bandpass noise bursts (5–18 kHz) were used to create a signal and a masker. In the case of correlated stimuli, the same noise burst served both as a masker and a signal. In the case of uncorrelated stimuli, the signal and the masker were created from two different noise bursts. The masker was always on the right at an angle of 15 degrees. The signal was presented in one of three positions on the left: –18, –52, –86 degrees. The signal and the masker of 1 s duration each were presented either simultaneously or with a shift of the signal onset relative to the masker onset. The delay varied from 1 to 1200 ms. Perceived position of signals under masking conditions were compared with a single presentation of the signal. It is shown that under the masking conditions the perceived position of the signal shifted towards the masker, and the perceived position of the masker shifted towards the signal. The shift value decreased with increasing delay between the signal and the masker and with increasing angular distance between them. The mutual influence of the signal and the masker was more pronounced for correlated stimuli than for uncorrelated ones.