3D acoustic source localization in the spherical harmonic domain based on optimized grid search

An approach for 3D source localization using a spherical microphone array is proposed that gives improved accuracy compared to intensity-based methods. First order spherical harmonics are first used to obtain an initial approximate localization result and then the initial result is improved based on an optimized grid search in the local vicinity using the method of least squares and high-order spherical harmonics. We show that this approach outperforms the first-order approach and shows strong robustness to reverberation and noise. The worst average error of 3 degrees was found in our experiments in the presence of realistic reverberation and noise.