Article
First and Higher-Order Diffraction Rendering for Interactive Virtual Acoustics (en)
* Presenting author
Abstract:
Virtual acoustics can be used to create complex acoustic environments with a broad range of applications in hearing research, architectural planning, and entertainment. For real-time simulations, a computational efficient approach is to use geometrical acoustics (GA), which approximates sound as rays that follow straight paths. However, in real sound fields, diffraction leads to perceptually relevant effects, particularly when sound sources become occluded. To approximate diffraction in the framework of GA, additional diffraction paths are modeled and combined with the direct sound and specular reflections (image sources). Recent filter-based approaches enable the computationally-efficient spectral representation of first-order edge diffraction. For interactive virtual acoustics with moving sources and receivers, two aspects are highly relevant: i) perceptually correct binaural rendering of edge-diffracted sounds, and ii) a continuous simulated sound field to achieve smooth transitions between conditions with, e.g., occluded and visible sources.Here, strategies to binaurally render diffracted sound sources considering the perceived sound source location and to account for spectral effects of higher-order diffraction are presented and discussed with regard to spatial smoothness. Higher-order diffraction is considered for subsequent diffraction at room corners, and repeated diffraction at a flat (finite) object. For this, filter-based approaches are compared to numerical reference simulations.