Difference of the perceived auditory space between walking and passive self-motion

Abstract

We are investigating how auditory space was represented during linear self-motion (Teramoto et al., 2013). Several studies have suggested that whether the listener's motion is active or passive affected sound localization (Hirahara et al., 2013). In the present study, therefore, we set up three conditions: active motion condition, passive motion condition, and no motion condition. In active motion condition, observers were walking straight ahead. In passive motion condition, observers were transported forward by a robotic wheelchair. During the self-motion, a short noise burst was presented from one of the loudspeakers which were aligned parallel to the traveling direction when the listener's coronal plane reached the location of one of the speakers (null point). The listeners 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 experiment showed that the sound position aligned with the subjective coronal plane was displaced compared with the null point. However, there was no significant difference between auditory space in active and passive motion conditions. This result suggests only action of the kinetic system during self-motion and planning and execution of voluntary movement would not affect perceived auditory space.