Beta-order minimum mean-square error multichannel spectral amplitude estimation for speech enhancement

In this paper, the minimum mean-square error (MMSE) β-order estimator for multichannel speech enhancement is proposed. The estimator is an extension of the single-channel MMSE β-order and multichannel MMSE short-time spectral amplitude estimators using Rayleigh and Gaussian distributions for the statistical models under the assumption of a diffuse noise field where the noise is estimated independently across each of the microphones. Experiments are performed to evaluate the new estimator against the baseline single-channel and multichannel estimators using various values of the β parameter and number of microphones along with different levels of noises as a function of the input signal-to-noise ratio. By the utilization of additional microphones, the multichannel MMSE β-order estimator achieves performance gains in noise reduction, speech distortion, and speech quality as measured by the segmental signal-to-noise ratio, log-likelihood ratio, and perceptual evaluation of speech quality objective metrics.