A real time robust adaptive microphone array controlled by an SNR estimate

A robust adaptive microphone array (RAMA) using a new adaptation-mode control method (AMC) is proposed, and its evaluation results by hardware are presented. The adaptation of the RAMA is controlled based on an SNR (signal-to-noise) estimate using the output powers of the fixed beamformer and the adaptive blocking matrix. The RAMA is implemented on a multi-DSP real time signal-processing system with a C-compiler. Simulation results with real acoustic data show that the AMC based on the SNR estimate causes less breathing noise than the conventional AMC and that it obtains 1.0-point higher score on a 5-point mean opinion score scale. Evaluation through a real time signal-processing system demonstrates that noise reduction achieved by the RAMA is over 12 dB even in reverberant environments.