针对常规二元麦克风小阵列话音增强算法通常需要话音活动检测技术支持,并且难以有效抑制第一帧含目标信号的噪声。提出了一种基于多任务稀疏表达的二元麦克风小阵列话音增强算法,首先利用字典学习方法分别获得目标信号和噪声信号的过完备字典,然后利用e2/e1混合范数对信号在其字典上的表示系数进行正则化稀疏约束,使得2个阵元接收到信号中的噪声信号被抑制,而话音信号尽量保持不变,从而达到话音增强的目标。仿真和实验数据表明,无论开始位置是否含有目标话音信号,所提出的非话音活动检测支持的二元麦克风小阵列话音增强算法均能有效实现话音增强的目标。
Speech enhancement algorithms for dual small microphone arrays usually rely on the voice activity detec- tion(VAD), and they may fail in some cases when target speech signal is included in the first frame. A multi-task sparse representation based speech enhancement algorithm was proposed. First, dictionaries for signal and noise were respec- tively formed via dictionary learning. Then the noise in signals obtain from two microphones was reduced by ~2/~t regu- larized sparse representation on the over-complete dictionary, while the target speech signals were mostly preserved, hence the speech signals were enhanced. Experimental results from synthetic and real-world data show that the proposed speech enhancement algorithm without VAD works well in all cases no ~natter speech signal is included in the first frame or not.