Outdoor Sound Propagation in Inhomogeneous Atmosphere via Precomputation

Abstract

Most of the sound propagation simulation methods are dedicated to room scenes, and only few of them can be used for outdoor scenes. Meanwhile, although ray tracing is used for simulation, it cannot accurately simulate some acoustic effects. In acoustics, some wave-based methods are accurate but suffer from low computational efficiency. We present a novel wave-based precomputation method that enables accurate and fast simulation of sound propagation in inhomogeneous atmosphere. An extended FDTD-PE method is used to calculate the sound pressure in 3D scene. The space is divided into two parts, the source region in which the FDTD method is employed and the far-field region in which the PE method is employed. A coupling methodology is applied at the junction between the two regions. The sound pressure data is further compressed to get the impulse response (IR) of the source region and sound attenuation function of the far-field region. Finally, we validated our method through various experiments, and the results indicate that our method can accurately simulate the sound propagation, with quite higher speed and lower storage.