Method for increasing lateral perceived azimuth of binaural reproduction over two loudspeakers

Abstract

In binaural reproduction over loudspeakers (BROL), at the target azimuth beyond the span angle of loudspeakers, the lateral perceived azimuth is usually smaller than the corresponding target azimuth, which is a major intrinsic limitation of BROL. To increase the perceived azimuth of binaural reproduction over two loudspeakers, a perceptually motivated method with low-computational complexity is proposed in this study. Based on the out-of-phase characteristics between the low-frequency amplitude of the two reproduction loudspeakers when the target azimuth is outside the span angle of loudspeakers, the proposed method widens the lateral perceived azimuth by increasing the low-frequency amplitude of the contralateral loudspeaker, which is the loudspeaker on the contralateral side of the target azimuth. Moreover, the amplitude required to be increased for the contralateral loudspeaker can be obtained through velocity vector synthesis. Objective analysis indicates that the proposed method affords a greater interaural phase delay difference than the conventional BROL. Additionally, this method alleviates the lack of dynamic cues to some extent. The results of the subjective listening experiment show that the proposed method can significantly increase the lateral perceived azimuth for different stimuli without introducing additional unnatural perception.