Short-term effects of sound localization training in virtual reality
Abstract. Head-related transfer functions (HRTFs) capture the direction-dependant way that sound interacts the head and torso. In virtual audio systems, which aim to emulate these effects, non-individualized, generic HRTFs are typically used, leading to inaccurate virtual sound localization. Training has the potential to exploit the brain's ability to adapt to these unfamiliar cues. In this study, three virtual sound localization training paradigms were evaluated; one provided simple visual positional confirmation of sound source location, a second introduced game design elements ("gamification") and a final version additionally utilized head-tracking to provide listeners with experience of relative sound source motion ("active listening"). The results demonstrate a significant effect of training after a small number of short (12-minute) training sessions, which is retained across multiple days. Gamification alone had no significant effect on the efficacy of the training, but the inclusion of active listening resulted in a significantly greater improvement in virtual sound localization accuracy. Improvements in polar angle judgement were significantly larger for the trained HRTFs, while improvement in lateral judgements and front-back reversals also generalized to a second set of HRTFs, for which no positional feedback was given. The implications of this on the putative mechanisms of the adaptation process are discussed.