An integrated real-time beamforming and postfiltering system for nonstationary noise environments
An integrated real-time beamforming and postfiltering system for nonstationary noise environments
复制标题
DOI：
10.1155/s1110865703305050
复制
发表时间：
2003-10-01
期刊：
影响因子：
--
通讯作者：
Berdugo, B
中科院分区：
文献类型：
--
作者：
Cohen, I;Gannot, S;Berdugo, B
提出了一种在非平稳噪声和时变声学传递函数（ATF）环境中进行实时多通道语音增强的新方法。该系统集成了自适应波束形成、ATF识别、软信号检测和多通道后置滤波。波束形成器的噪声消除分支和ATF辨识基于假设检验结果自适应地在线更新。噪声消除器仅在平稳噪声帧期间更新，并且仅当已经检测到期望的源分量时执行ATF识别。假设检验基于信号的非平稳性和波束形成器主输出与其参考噪声信号之间的瞬态功率比。波束形成和假设检验后，估计的信号存在概率和噪声功率谱密度。随后，最佳的频谱增益函数，最大限度地减少了对数频谱幅度（LSA）的均方误差。实验结果表明，该系统在非平稳噪声环境中的有效性。
We present a novel approach for real-time multichannel speech enhancement in environments of nonstationary noise and time-varying acoustical transfer functions (ATFs). The proposed system integrates adaptive beamforming, ATF identification, soft signal detection, and multichannel postfiltering. The noise canceller branch of the beamformer and the ATF identification are adaptively updated online, based on hypothesis test results. The noise canceller is updated only during stationary noise frames, and the ATF identification is carried out only when desired source components have been detected. The hypothesis testing is based on the nonstationarity of the signals and the transient power ratio between the beamformer primary output and its reference noise signals. Following the beamforming and the hypothesis testing, estimates for the signal presence probability and for the noise power spectral density are derived. Subsequently, an optimal spectral gain function that minimizes the mean square error of the log-spectral amplitude (LSA) is applied. Experimental results demonstrate the usefulness of the proposed system in nonstationary noise environments.