Acoustic redirected walking with auditory cues by means of wave field synthesis

We present an experiment to identify detection thresholds for acoustic redirected walking by means of wave field synthesis. The most natural way to navigate an avatar through an immersive virtual environment (IVE) is by copying the tracked physical movements of a user. Redirected walking offers an approach to tackle the discrepancy between the potentially infinite IVE and the generally limited available physical space or tracking area, by applying manipulations, such as rotations or translations, to the IVE in form of gains to the users movements. 39 blindfolded test subjects performed a total of 2777 constant stimulus trials with various amounts of rotation and curvature gains. The test subjects were divided into four groups with different knowledge of the experiment, and one group performed two-alternative-forced-choice tasks, while the others could give feedback freely. The detection thresholds were greatly dependent on the groups i.e., the knowledge of the experiment. The 25% detection threshold was reached by the most relevant test group at gains that up-scaled rotations by 5%, down-scaled them by 37.5%, and bend a straight path into a circle with a radius of 5.71 meters. Almost no signs of simulator sickness could be observed.