Sound field analysis with concentric spherical microphone arrays
A dual concentric spherical microphone array (SMA) provides advantages in terms of the frequency range of operation. In Figure 1, we show the first dual concentric SMA of its kind. We use an array with 32 microphones on the inner sphere and 32 microphones on the outer sphere. The acoustic scattering effects of the rigid inner sphere on the outer sphere are appropriately treated using phase-mode beamforming. For improved signal-to-noise ratio when beamforming, we apply modal processing that combines information across the two different spherical arrays. Sound field analyses in the spherical harmonic domain demonstrates interesting advantages for sound separation, sound localisation, and acoustic holography.
Figure 1: The CARLab dual concentric spherical microphone array
Selected Research Articles
(2010) Epain, N., Jin, C.T., van Schaik, A., Blind source separation using independent component analysis in the spherical harmonic domain, In Proceedings of the 2nd International Symposium of Ambisonics and Spherical Acoustics (Paris 2010), 1-6.
(2009) Parthy, A., Jin, C.T., van Schaik, A., Acoustic holography with a concentric rigid and open spherical microphone array, International Conference on Acoustics, Speech and Signal Processing, 2173-2176.
(2010) Epain, N., Jin, C.T., van Schaik, A., The application of compressive sampling to the analysis and synthesis of spatial sound fields, Proceedings of the 127th Convention of the Audio Engineering Society (New York 2009), Paper 7857: 1-12.