Abstract: A subband spectral-subtraction method for speech enhancement was proposed. Time series were decomposed into frequency subbands through the filterbank and in each subband, an improved spectral-subtraction technique was applied. This method mainly considered that most environmental noises would affect the speech spectrum nonuniformly within different frequencies and multiband processing would be more accurate and effective. In the speech processing experiments, objective evaluation reveals that the proposed algorithm performs well in noise suppression and speech quality improvement, which makes the speech after processing more comfortable and intelligible.

Key words: speech enhancement, spectral-subtraction, filter bank, subband processing, noise suppressing

摘要： 为了抑制语音信号中的环境噪声，提出了一种基于子带谱减法进行噪声抑制的语音增强方法。首先通过滤波器组将时域信号分成若干个频（子）带，然后在每个子带中，独立使用改进的谱减法技术进行语音增强。由于实际环境中的背景噪声绝大多数都不是随频率均匀分布的，因此这种在不同频带内进行噪声估计和频谱相减的方法更具有针对性，且更加准确。在实际语音处理实验中证明，所提方法在达到噪声抑制效果的同时较好地保留了语音的结构，使增强后的语音具有更高的听觉舒适度和可理解度。

关键词: 语音增强, 谱减法, 滤波器组, 子带处理, 噪声抑制