A binaural model that analyses acoustic spaces and stereophonic reproduction systems by utilizing head rotations

Abstract

It is well known that head rotations are instrumental in resolving front/back confusions in human sound localization. A mechanism for a binaural model is proposed here to extend current cross-correlation models to compensate for head rotations. The algorithm tracks sound sources in the head-related coordinate system, HRCS, as well as in the room-related coordinate system, RRCS. It is also aware of the current head position within the room. The sounds are positioned in space using an HRTF catalog at azimuthal resolution. The position of the sound source is determined through the interaural cross-correlation, ICC, functions across several auditory bands that are mapped to functions of azimuth and superposed. The maxima of the cross-correlation functions determine the position of the sound source. Unfortunately, two peaks usually occur, one at or near the correct location and the second at the front/back reversed position. When the model is programmed to virtually turn its head, the degree-based cross-correlation functions are shifted with the current head angle to match the RRCS. During this procedure, the ICC peak for the correct hemisphere will prevail if integrated over time for the duration of the head rotation, whereas the front/back reversed peak will average out.