Effects of Head-Tracking Artefacts on Externalization and Localization in Azimuth With Binaural Wearable Devices

Head tracking combined with head movements have been shown to improve auditory externalization of a virtual sound source and contribute to the performance in localization. With certain technically constrained head-tracking algorithms, as can be found in wearable devices, artefacts can be encountered. Typical artefacts could consist of an estimation mismatch or a tracking latency. The experiments reported in this article aim to evaluate the effect of such artefacts on the spatial perception of a non-individualized binaural synthesis algorithm. The first experiment focused on auditory externalization of a frontal source while the listener was performing a large head movement. The results showed that a degraded head tracking combined with head movement yields a higher degree of externalization compared to head movements with no head tracking. This suggests that the listeners could still take advantage of spatial cues provided by the head movement. The second experiment consisted of a localization task in azimuth with the same simulated head-tracking artefacts. The results showed that a large latency (400 ms) did not affect the ability of the listeners to locate virtual sound sources compared to a reference headtracking. However, the estimation mismatch artefact reduced the localization performance in azimuth.