Effect of an auditory static distractor on the perception of an auditory moving target

TL;DR

This study investigates how a static auditory distractor affects the ability to perceive the direction of a moving sound, revealing that spectral overlap with the target reduces the upper velocity limit for accurate discrimination.

Contribution

It demonstrates that static distractors impair auditory motion perception and that spectral overlap specifically reduces the upper velocity limit for discrimination.

Findings

Static distractors lower the upper limit of motion discrimination.

Spectral overlap between distractor and target reduces the velocity limit.

Distractors at different spatial locations are equally effective in impairing perception.

Abstract

It is known that listeners lose the ability to discriminate the direction of motion of a revolving sound (clockwise vs. counterclockwise) beyond a critical velocity ("the upper limit"), likely due to degraded front-back discrimination. Little is known about how this ability is affected by simultaneously present distractor sounds, despite the real-life importance of tracking moving sounds in the presence of distractors. We hypothesized that the presence of a static distractor sound would impair the perception of moving target sounds and reduce the upper limit, and show that this is indeed the case. A distractor on the right was as effective as a distractor at the front in reducing the upper limit despite the likely importance of resolving front-back confusions. By manipulating the spectral content of both the target and distractor, we found that the upper limit was reduced if and only if the distractor spectrally overlaps with the target in the frequency range relevant for front/back discrimination. Our findings form the first steps toward a better understanding of the tracking of multiple sounds in the presence of distractors.