Convention Paper
Video-Based Head Tracking for Improvements in Multichannel Loudspeaker Audio
AES Convention 105 · Paper 4845 · September 1998
Abstract
Multichannel audio rendering systems can benefit greatly from tracking the coordinates of the listener's head. In two-channel stereo, head tracking allows dynamic adjustment of the time of arrival of sound from each loudspeaker so that the listener is always placed in the sweet spot. For 5.1 channel material rendered over 5.1 loudspeakers, head tracking can be used to account for imaging distortion that occurs when the listener is outside the optimum listening area. Finally, in 5.1 channel material rendered over 2 (or 2.1) loudspeakers using 3-D audio signal processing techniques, knowing the location of the listener's head is the most critical factor that affects the performance of such systems. The crosstalk cancellation filters required to render virtual loudspeaker positions are critically dependent on precise positioning of the listener's ears. Without head tracking and dynamic adjustment of filter parameters in response to head movement, the functionality of such systems is extremely limited. In this paper we present a video-based architecture for tracking the listener unobtrusively combined with a novel approach to crosstalk filter design that can be modified in real time based on information provided by the head tracking algorithm.
