SPEECH ENHANCEMENT USING NEAR-FIELD SUPERDIRECTIVITY WITH AN ADAPTIVE SIDELOBE CANCELER AND POST-FILTER

This paper describes a new microphone array technique and investigates its effectiveness for speech enhancement. A system structure consisting of a fixed near-field superdirective beamformer and an adaptive sidelobe canceling path is proposed (NFSD-ASC). The effect of adding a post-filter is also examined. The system is evaluated in terms of speech quality measures in the context of a computer workstation in an office environment. The speaker is located directly in front of the computer monitor at a distance of 60 cm and the array is designed to fit across the top of a standard 17 inch monitor. The experiments show that the array is effective in both decreasing the noise level and the amount of signal distortion when compared with standard near-field superdirectivity and the generalised sidelobe canceler.

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