Tutorial on finite-difference time-domain (FDTD) methods for room acoustics simulation

Wave-based simulation models for acoustics have remained an active area of research and development for the past three decades. Wave-based methods aim to solve the 3D wave equation directly and therefore have large computational costs relative to conventional ray-based methods, which tend to simplify wave-diffraction effects. However, wave-based methods offer the potential of complete numerical solutions, including all wave-scattering and diffraction effects over the full audible bandwidth. Additionally, wave-based methods are highly parallelisable, making them amenable to parallel computing architectures such as graphics processing units, which can greatly cut down lengthy simulation times. This tutorial will give an introduction to wave-based methods for room acoustics with a focus on the finite-difference time-domain (FDTD) method. The basic concepts behind FDTD methods, along with practical implementation issues, will be discussed and illustrated with examples. The relationship of FDTD methods to other wave-based methods, along with differences to ray-based methods, will be explained. Also, the use of graphics processing units (GPUs) with freely available FDTD software will be discussed.