关键词: 语音增强, 语音存在概率, 广义Gamma分布, 最小均方误差, 对数谱

Abstract: This paper presents a modified speech enhancement algorithm under signal presence probability. Generalized Gamma distribution priors are assumed for speech short-time spectral amplitudes, which is more flexible in capturing the statistical behavior of speech signals. It derives a Minimum Mean-Square Error（MMSE） estimator of the log-spectra amplitude for speech signals, under the assumption of a generalized Gamma speech priors and additive Gaussian noise priors. Furthermore, modification under signal presence probability is obtained, which is estimated for each frequency bin and each frame consistent with the new model. The simulation results show that the proposed algorithm achieves better noise suppression and lower speech distortion compared to the conventional short-time spectral amplitude estimators, which are based on Gaussian and super-Gaussian speech model.

Key words: speech enhancement, speech presence probability, generalized Gamma distribution, Minimum Mean-Square Error（MMSE）, log-spectral