Use of n-perturbation interval ray tracing method in predicting acoustic field distribution

Abstract

To predict the acoustics of a room based on a computer simulation, we must know its dimensions and shape, the acoustic properties of the partitioning materials, and information regarding the objects contained within it. Most frequently, we do not know the exact acoustic properties of such materials, and we are unable to consider all elements present in the room and their impact on the reflections, refractions, or dispersions of the sound waves. Therefore, in this paper, an algebraic system applying n-perturbation intervals allowing for room disturbances that affect the final result of the estimated acoustic properties is proposed. First, the applied algebraic formula is presented, and the algorithm system for the ray tracing method based on perturbation methodology is then proposed. The determination of uncertainty based on the n-perturbation interval method was verified through a comparison with the approach described in the “Guide to the expression of uncertainty in measurement” and with the Monte Carlo method. A numerical example is also demonstrated, by which the disturbed distribution of the acoustic field in a room can be determined. Actual measurements verify the results described in this study. The measurements were conducted in a reverberation chamber, which was used as a test room.