结合相位谱补偿的调制域谱减法

Modulation Domain Spectral Subtraction Combined with Phase Spectrum Compensation

  • 摘要: 针对现有谱减法面临增强语音可懂度低且引入“音乐噪声”的问题,提出了一种结合相位谱补偿的调制域谱减法。首先将语音分解到若干频带,以同一频带不同时间的幅度谱为输入,通过傅里叶变换得到调制谱,然后采用谱减法修正不同频带的调制幅度谱,有效抑制了背景噪声,同时利用反对称函数补偿调制相位谱,进一步降低残留噪声,提高了语音可懂度。主客观实验结果表明,在不同噪声及信噪比情况下,本文方法能明显抑制背景噪声和“音乐噪声”,同时处理后的增强语音保持良好的语音可懂度,改善了主观感知质量。

     

    Abstract: It is well known that the enhanced speech of existing spectral subtraction algorithms has low intelligibility and will introduce "musical noise". In order to resolve these problems, a modulation domain spectral subtraction combined with phase spectrum compensation will be introduced. The noisy speech signal was divided into several subbands by using the first Fourier transform in this algorithm, and the modulation spectrum was got by using the second Fourier transform on every subband at different times. Then, spectral subtraction method was used on the modulation magnitude spectrum of different subbands, the reduction of background noise was significantly improved. And a modulation phase spectrum compensative method was presented by using an antisymmetry function to further suppress the remaining noise and improve speech intelligibility. Both subjective and objective experimental results under some kinds of noise and different signal-to-noise ratios demonstrate that the modulation domain spectral subtraction combined with phase spectrum compensation is more competitive as compared to the existing spectral subtraction algorithms. The method of this paper significantly reduced the background noise and “musical noise” . In addition, the enhanced speech signal keeps favourable intelligibility and improves subjective perception quality.

     

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