High-order wave decomposition using a dual-radius spherical microphone array

The acoustic performance of an auditorium is influenced by the manner in which sound propagates from the stage into the seating areas. In particular, the spatial and temporal distribution of early reflections is considered important for sound perception in the auditorium. Previous studies presented measurement and analysis methods based on spherical microphone arrays and plane‐wave decomposition that could provide information on the direction and time of arrival of early reflections. This paper presents recent results of room acoustics analysis based on a spherical microphone array, which employs high spherical harmonics order for improved spatial resolution, and a dual‐radius spherical measurement array to avoid ill‐conditioning at the null frequencies of the spherical Bessel function. Spatial‐temporal analysis is performed to produce directional impulse responses, while time‐windowed space‐frequency analysis is employed to detect direction of arrival of individual reflections. Experimental results of sound‐field analysis in a real auditorium will also be presented.