The Effect of Spatial Audio on Thresholds for Curvature Gains in Redirected Walking Applications in Virtual Reality

Abstract

Redirected walking (RDW) is a technique used in virtual reality (VR) applications to allow users to navigate virtual environments that are larger than the physical space they are walking in. RDW works by decoupling the user’s virtual trajectory from their real trajectory, and is achieved by manipulating the view of the virtual world presented to the user via a head-mounted display (HMD). The success of this technique depends on the dominance of vision in orientation perception. However, there are limitations to how much the orientation can be manipulated before the user notices and the illusion is broken. This study aims to investigate the effect of adding spatial audio elements to RDW in order to increase the perceptual threshold and allow for higher levels of redirection while maintaining a convincing experience. This research conducts user experiments with a population of n=18, under conditions with and without spatial audio elements, to research the perceptual thresholds. The tested curvature gains range of 0°/m, 3°/m, 6°/m and 9°/m, to both the left and right. An increase in detection threshold of 2.56°/m is found between conditions with and without audio, which leads to a detection threshold of 8.7°/m when spatial audio elements are applied. This positive effect on thresholds could allow for higher levels of redirection when spatial audio is applied, while maintaining a convincing experience, leading to more freedom to navigate virtual environments in even smaller physical spaces.