Comparative evaluation of ray tracing and diffusion equation modeling in room acoustics design of subway stations

Abstract

Due to their disproportionate geometries and uneven distribution of sound, the interior sound field analysis of subway stations has always been challenging. The field necessitates reliable tools for real-case design applications, while the research and discussions on the topic are still ongoing. This study compares two major room acoustics simulation approaches, namely ray tracing and diffusion equation modeling (DEM) in order to assist future acoustical designs of subway stations. Two cases of Istanbul Metropolitan metro lines are selected, namely station BAG with a circular cross section and station USK with rectangular cross section. The reverberation time and relative sound pressure level results from field tests are compared with those obtained by the ray tracing and DEM. The results emphasized the validity as well as limitations of each method over discussed metrics with given geometric layouts and material characteristics of the subway stations.