Rapid Auditory System Adaptation Using a Virtual Auditory Environment

Abstract

Various studies have highlighted plasticity of the auditory system from visual stimuli, limiting the trained field of perception. The aim of the present study is to investigate auditory system adaptation using an audio-kinesthetic platform. Participants were placed in a Virtual Auditory Environment allowing the association of the physical position of a virtual sound source with an alternate set of acoustic spectral cues or Head-Related Transfer Function (HRTF) through the use of a tracked ball manipulated by the subject. This set-up has the advantage to be not being limited to the visual field while also offering a natural perception-action coupling through the constant awareness of one's hand position. Adaptation process to non-individualized HRTF was realized through a spatial search game application. A total of 25 subjects participated, consisting of subjects presented with modified cues using non-individualized HRTF and a control group using individual measured HRTFs to account for any learning effect due to the game itself. The training game lasted 12 minutes and was repeated over 3 consecutive days. Adaptation effects were measured with repeated localization tests. Results showed a significant performance improvement for vertical localization and a significant reduction in the front/back confusion rate after 3 sessions.