Phase-Based Dual-Microphone Speech Enhancement Using A Prior Speech Model

Guangji Shi, Parham Aarabi, Hui Jiang
2007 IEEE Transactions on Audio, Speech, and Language Processing  
This paper proposes a phase-based dual-microphone speech enhancement technique that utilizes a prior speech model. Recently, it has been shown that phase-based dual-microphone filters can result in significant noise reduction in low signal-to-noise ratio [(SNR) less than 10 dB] conditions and negligible distortion at high SNRs (greater than 10 dB), as long as a correct filter parameter is chosen at each SNR. While prior work utilizes a constant parameter for all SNRs, we present an SNR-adaptive
more » ... filter parameter estimation algorithm that maximizes the likelihood of the enhanced speech features based on a prior speech model. Experimental results using the CARVUI database show significant speech recognition accuracy rate improvement over alternative techniques in low SNR situations (e.g., an improvement of 11% in word error rate (WER) over postfiltering and 23% over delay-and-sum beamforming at 0 dB) and negligible distortion at high SNRs. The proposed adaptive approach also significantly outperforms the original phase-based filter with a constant parameter. Furthermore, it improves the filter's robustness when there are errors in time delay estimation. Index Terms-Microphone array, phase-error filtering, robust speech recognition, speech enhancement, time-frequency masking.
doi:10.1109/tasl.2006.876870 fatcat:djtnc7dz4vazhismmzj2627fsi