An Algorithm for Generating Virtual Sources in Dynamic Virtual Auditory Display Based on Tensor Decomposition of Head-Related Impulse Responses

Abstract

Dynamic virtual auditory displays (VADs) are increasingly used for generating various auditory objects and scenes in virtual and augmented reality. Dynamic VADs are required to generate virtual sources in various directions and distances by using HRTF- or HRIR-based binaural synthesis. In the present work, an algorithm for improving the efficiency and performance of binaural synthesis in dynamic VAD is proposed. Based on tensor decomposition, a full set of near-field HRIRs is decomposed as a combination of distance-, direction-, and time-related modes. Then, binaural synthesis in VAD can be implemented by a common set of time mode-related convolvers or filters associated with direction- and distance-related weights. Dynamic binaural signals are created by updating the weights rather than updating the HRIR-based convolvers, which enables the independent control of virtual source distance and direction and avoids the audible artifact caused by updating the HRIR-based convolvers. An example of implementation indicates that a set of eight common convolvers or filters for each ear is enough to synthesize the binaural signals with sufficient accuracy. The computational efficiency of simultaneously generating multiple virtual sources is improved when the number of virtual sources is larger than eight. A virtual-source localization experiment validates the algorithm.