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Proceedings Joint Workshop on Hands-free Speech Communication and Microphone Arrays (HSCMA 08), 53-56, Trento, Italy, 2008.


Tobias Wolff, Markus Buck

Spatial maximum a posteriori post-filtering for arbitrary beamforming


We present a new approach for residual transient noise suppression at the output of an arbitrary beamformer. A spatial optimum esti­mate for the instantaneous a posteriori SNR is derived on the basis of the output signals of a blocking matrix. The optimization prob­lem is formulated in the logarithmic domain and statistical models for the obtained quantities are given. Based on these models the op­timization problem is solved in the maximum a posteriori sense. It is shown that the performance of speech recognition systems in non-stationary noise scenarios is improved considerably compared to the performance achieved with a Wiener filter applied to the beamformer output.

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