Stefan Bilbao: Wave-based Time Domain Methods in Room Acoustics Auralisation

This video is of a webinar held on Friday 10th March 2023 by the Computational Acoustics Special Interest Group of the UK Acoustics Network. The speaker is Prof. Stefan Bilbao, Chair of Acoustics and Audio Signal Processing at the University of Edinburgh.

Abstract: Room acoustics simulation is computationally-heavy, no matter how it is undertaken. Auralisation, requiring output at an audio rate, is even more so. The majority of room acoustics simulation and auralisation techniques derive from geometric acoustics (GA) approximations to the solution to the 3D wave equation over an enclosure; these include ray-tracing and the image source method. But GA methods represent only an approximation to room acoustics in the limit of high frequencies. In particular, effects of diffraction are neglected. Wave-based methods allow a complete solution to the problem of auralisation---and yet, many new wrinkles appear, relating to the major issues of efficiency, numerical stability and accuracy. In this talk, the most basic wave-based time domain method, the finite difference time domain (FDTD) method will be outlined, and various features will be discussed in detail. The generalisation to the finite volume time domain (FVTD) method will then be described. The talk will conclude with a presentation of various new directions, including achieving higher order accuracy, immersed boundaries, and the modeling of frequency-dependent source directivity and spatial encoding.