A parametric model for the synthesis of binaural room impulse responses

Abstract

Binaural room impulse responses (BRIRs) are often applied in spatial audio for the auralization of acoustical environments. In the same field of research, parametric audio coding is an established approach and part of different standards. The presented investigation aims for a parametric description of the sound field to synthesize BRIRs. The model focuses on the main features which characterize a BRIR as well as the acoustical environment. Thereto a spherical microphone array is applied for a spatio-temporal acoustical analysis. Early reflections are determined with sound field decomposition techniques and are described by directional parameters. Diffuse components and the interaural coherence of the late reverberation are characterized with diffuse parameters. In two previous studies, the synthesis of the early and the late part of BRIRs has been elaborated and perceptually evaluated apart from each other. Now both approaches are combined to synthesize entire BRIR datasets using the parametric approach. Fundamentals of the sound field analysis are explained and synthetic BRIRs are compared to their measured counterparts. The approach yielded satisfactorily results and an adequate auralization based on parameters. Surprisingly no relevant enhancement of the auralization due to the additional use of reflections in contrast to diffuse components only could be observed.