Abstract  Description  Claims  Drawing  Search report  Cited references 

US6001131A   [0003] 
US20100070266A1   [0004] 
US20050255843A1   [0050] 

Maximum Likelihood Based Noise Covariance Matrix Estimation for Multi-Microphone Speech Enhancement   [0063] 
Adaptive Filter Theory   [0070] 
Speech Enhancement: Theory and Practice   [0075]