Localization of a Target Sound Source in the Presence of Fixed, Random, and Moving Distractor Sources

Abstract

While a great deal is known about the cues that permit listeners to identify the location of a sound source (i.e., sound localization), little research has been done on localization ability in the presence of multiple sound sources. The present series of experiments examined the ability of listeners to localize a target sound source in the presence of an additional distractor sound source. The listener sat in the center of an array of 36 loudspeakers positioned every 10 degrees in azimuth in the horizontal plane (at ear level, laterally about the listener). On each trial, a target was played from a different, randomly chosen loudspeaker. The listener's task was to point with a laser pointer at the apparent location of the target. Performance was assessed in conditions in which the target was presented (1) in isolation, (2) in the presence of a distractor that was fixed in position across trials, (3) in the presence of a distractor that was presented at a different randomly chosen position in each trial, and (4) in the presence of a distractor that moved across a distance of 50 degrees in azimuth during each trial. The data were analyzed in terms of the correlation and standard deviation between the true target location and the perceived location to identify interference that might be produced by the different types of distractors.