Requirements for Spatial Resolution of Late Reverberation in Virtual Acoustic Environments
* Presenting author
Abstract:
In room acoustics simulations and sound field rendering, diffuse late reverberation can be approximated by only using a limited number of spatially distributed virtual reverb sources (VRS) radiating incoherent signals. The advantage of such a simplification is a reduced computational effort for the simulation and rendering of late reverberation. A limited number of VRS, however, may potentially create differences to the desired spatial coherence of the reverberant sound field.This contribution assesses the minimum number of VRS required to achieve late reverberation that is both perceptually plausible and suitable for the technical evaluation of multi-microphone hearing device signal processing algorithms. The room acoustics simulator RAZR [Wendt et al., J. Audio Eng. Soc., 62, 11 (2014)] was used to generate early reflections and late reverberation. An 86-channel spherical loudspeaker array in an anechoic chamber was used for rendering. The spatial resolution of the late reverberation was systematically reduced by using subsets of the loudspeakers. It was tested whether listeners can distinguish lower spatial resolutions from the highest spatial resolution in different simulated rooms. In a technical evaluation, the approximation of the isotropic reference condition was evaluated to separate effects of loudspeaker array topology and number of VRS.