Real-time conversion of sensor array signals into spherical harmonic signals with applications to spatially localised sub-band sound-field analysis

This paper presents two real-time audio plug-ins for processing sensor array signals for sound-field visualization. The first plug-in utilizes spherical or cylindrical sensor array specifications to provide analytical spatial filters which encode the array signals into spherical harmonic signals. The second plug-in utilizes these intermediate signals to estimate the direction-of-arrival of sound sources, based on a spatially localized pressure-intensity (SLPI) approach. The challenge with the traditional pressure-intensity (PI) sound-field analysis is that it performs poorly when presented with multiple sound sources with similar spectral content. Test results indicate that the proposed SLPI approach is capable of identifying sound source directions with reduced error in various environments, when compared to the PI method.