An efficient finite-impulse-response filter model of head-related impulse response

Abstract

Head-related impulse responses (HRIRs) play a crucial role in binaural 3-D audio rendering. The HRIRs with a couple of hundred-sample lengths result in the high computation cost for the real-time 3-D audio applications especially when multiple sound sources are rendered simultaneously. To overcome this problem, various modeling approaches have been reported to reduce the number of parameters of HRIRs without sacrificing the quality of rendered sounds. In this research, an efficient finite-impulse-response (FIR) model is first studied, which is essentially based on the concept of the minimum-phase modeling technique. In this method, the measured HRIRs are represented by the interaural time delay (ITD) and the magnitude spectra that are approximated by two FIR filters. To investigate the accuracy dependence of this modeling approach on the order of FIR filter, two psychoacoustic experiments on sound localization and sound quality were conducted by comparing the synthesized stimuli with the measured HRIRs and those with the FIR models of different orders. Experimental results indicated that the measured hundred-sample-length HRIRs can be sufficiently modeled by the low-order (a dozen of coefficients) FIR model from the perceptual point of view. The derived low-order FIR model can be further applied to real-time 3-D audio applications.