Sound Propagation and Reconstruction Algorithm Based on Geometry

Abstract

This paper presents a method of simulating sound propagation and reconstruction for the virtual reality applications. The algorithm being developed in this paper is based on a ray sound theory. If we are given 3 dimensional geometry input as well as sound sources as inputs, we can compute sound effects over the entire boundary surfaces. In this paper, we present two approaches to compute sound field: The first approach, called forward tracing, traces sounds emanating from sound sources, while the second approach, called geometry based computation, computes possible propagation routes between sources and receivers. We compare two approaches and propose a geometry-based sound computation method for outdoor simulation. This approach is computationally more efficient than the forward sound tracing. The physical environment affects sound propagation simulation by impulse- response. When a sound source waveform and numerically computed impulse in time is convoluted, a synthetic sound is generated. This technique can be easily generalized to synthesize realistic stereo sounds for the virtual reality applications. At the same time, the simulation result can be visualized using VRML.