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.