Directional sound field decay analysis in coupled spaces

Abstract

Multi-exponential energy decays—showing a distinct curvature in the measured decay curve—are a well known phenomenon in coupled spaces if both spaces exhibit different reverberation times due to their specific absorption characteristics or volumes. Recently, Berzborn et al. (2019) investigated directional energy decay curves—calculated from a plane wave decomposition of the sound field—as an analysis framework for the angular distribution of energy during the decay process in reverberation rooms. In this contribution, we investigate the directional characteristics of the energy decay in two rooms connected by a door. Spherical microphone array measurements at two different receiver positions and coupling areas were performed. Results indicate a distinct anisotropic energy decay in the room with the shorter reverberation time, showing a decreased isotropy in the late decay process compared to the early part.