Effect of Active Self-Motion on Auditory Space Perception

Abstract

This study investigated how auditory space is represented during linear self-motion. Results of several studies suggest that whether the listener's motion is active or passive affects sound localization. Therefore, we investigated whether the style of the self-motion affects the perceived auditory space. As the passive condition, observers were transported automatically forward by a robotic wheelchair. In contrast, observers controlled the movement of the robotic wheelchair or walked straight ahead in active conditions. The observers indicated the direction in which the sound was perceived relative to their coronal plane (i.e., a two-alternative forced-choice task). The results of experiments demonstrated that the sound position aligned with the subjective coronal plane was displaced backward relative to the observers' physical coronal plane both in active and passive motion conditions. These results suggest that perceived self-motion itself affects auditory space representation irrespective of the intention of the movement.