A speech enhancement approach based on power level ratio of multi-beamformers

To improve the performance of the beamformer on spatial interference suppression and noise reduction, a method combining the Minimum Variance Distortionless Response (MVDR) beamformer and the Delay and Sum (DAS) beamformer is introduced. Based on the output power ratio of the two beamformers, a gain factor is defined, which is used to determine the diagonal loading value of the covariance matrix, as well as being a discrimination factor of the post-filtering. The calculation of the threshold of the discrimination factor is also introduced. Experiments in the circular microphone array show that the proposed method performs better in suppressing the interferences without decreasing the speech intelligibility.