Perceptual implications of simplifying geometrical acoustics models for Ambisonics-based binaural reverberation

Abstract

Different methods can be employed to render virtual reverberation, often requiring substantial information about the room's geometry and the acoustic characteristics of the surfaces. However, fully comprehensive approaches that account for all aspects of a given environment may be computationally costly and redundant from a perceptual standpoint. For these methods, achieving a trade-off between perceptual authenticity and model's complexity becomes a relevant challenge. This study investigates this compromise through the use of geometrical acoustics to render Ambisonics-based binaural reverberation. Its precision is determined, among other factors, by its fidelity to the room's geometry and to the acoustic properties of its materials. The purpose of this study is to investigate the impact of simplifying the room geometry and the frequency resolution of absorption coefficients on the perception of reverberation within a virtual sound scene. Several decimated models based on a single room were perceptually evaluated using the a multi-stimulus comparison method. Additionally, these differences were numerically assessed through the calculation of acoustic parameters of the reverberation. According to numerical and perceptual evaluations, lowering the frequency resolution of absorption coefficients can have a significant impact on the perception of reverberation, while a less notable impact was observed when decimating the geometry of the model.