Audibility of dispersion error in room acoustic finite-difference time-domain simulation as a function of simulation distance

Finite-difference time-domain (FDTD) simulation has been a popular area of research in room acoustics due to its capability to simulate wave phenomena in a wide bandwidth directly in the time-domain. A downside of the method is that it introduces a direction and frequency dependent error to the simulated sound field due to the non-linear dispersion relation of the discrete system. In this study, the perceptual threshold of the dispersion error is measured in three-dimensional FDTD schemes as a function of simulation distance. Dispersion error is evaluated for three different explicit, non-staggered FDTD schemes using the numerical wavenumber in the direction of the worst-case error of each scheme. It is found that the thresholds for the different schemes do not vary significantly when the phase velocity error level is fixed. The thresholds are found to vary significantly between the different sound samples. The measured threshold for the audibility of dispersion error at the probability level of 82% correct discrimination for three-alternative forced choice is found to be 9.1 m of propagation in a free field, that leads to a maximum group delay error of 1.8 ms at 20 kHz with the chosen phase velocity error level of 2%.Peer reviewe

Auralization applying the parametric room acoustic modeling technique - the div auralization system

Presented at the 8th International Conference on Auditory Display (ICAD), Kyoto, Japan, July 2-5, 2002.The primary goal of this paper is to give a general view on room acoustic modeling and auralization, and especially to describe the current status of the DIVA auralization system. We have been building the system for several years, and it has evolved a lot during that time. It is a room acoustic modeling and auralization system suitable for both real-time and non-realtime acoustic rendering, and it is designed for research purposes. It applies the parametric room impulse response rendering technique described in the article. In this paper we review the architecture and design principles of the system. A description of recent advances is given and results of perceptual evaluations are presented