Binaural Coherence of Noise Fields

A semi-analytical model for the binaural noise field coherence.

A Matlab reference implementation of a novel semi-analytical signal processing model for the binaural coherence of homogeneous isotropic noise fields is presented.

The model is derived from a simplified geometrical model of the human head, where the shadowing between the left and right ear is modeled by two non-reflecting circular plates. Based on Kirchhoff’s diffraction theory, it is shown how the corresponding coherence is calculated. This model can be used as part of various binaural signal processing algorithms, such as speech enhancement for digital hearing aids or binaural speech transmission systems. In experiments using an artificial head in a highly reverberant environment, it is confirmed that the proposed theoretical model shows a good match with the coherence obtained from measurements.

Within this implmentation, arbitrary dimensions for head and microphone distances can be employed and no acoustic measurements are required.

Related paper:
M. Jeub, M. Dörbecker, P. Vary: "A Semi-Analytical Model for the Binaural
Coherence of Noise Fields", IEEE Signal Processing Letters, Vol.18, No.3,
March 2011 (DOI 10.1109/LSP.2011.2108284)