Finite-difference time-domain simulation of low-frequency room acoustic problems

This paper illustrates the use of a numerical time-domain simulation based on the finite-difference time-domain (FDTD) approximation for studying low- and middle-frequency room acoustic problems. As a direct time-domain simulation, suitable for large modeling regions, the technique seems a good ''brute force'' approach for solving room acoustic problems. Some attention is paid in this paper to a few of the key problems involved in applying FDTD: frequency-dependent boundary conditions, non-Cartesian grids, and numerical error. Possible applications are illustrated with an example. An interesting approach lies in using the FDTD simulation to adapt a digital filter to represent the acoustical transfer function from source to observer, as accurately as possible. The approximate digital filter can be used for auralization experiments. (C) 1995 Acoustical Society of America.