Blind source separation using independent component analysis in the spherical harmonic domain
Nicolas Epain, Craig Jin, and André van Schaik
Spherical microphone arrays provide a new and promising tool for the spatial analysis of complex sound fields. Most current frameworks, including HOA (Higher Order Ambisonics), rely on the spherical harmonic expansion of the sound field to form directional beams. Working in the spherical harmonic domain presents a number of advantages that include scalability (keeping the low-order components leads to a lower spatial resolution) and the ability to rotate the sound scene by a simple matrix operation on the signals. In this paper, we show that the spherical harmonic domain also provides significant advantages for the application of ICA (Independent Component Analysis) to separate and localise multiple sound sources.