@ARTICLE\{IMM2007-04875, author = "P. C. Hansen and S. H. Jensen", title = "Subspace-Based Noise Reduction for Speech Signals via Diagonal and Triangular Matrix Decompositions: Survey and Analysis", year = "2007", journal = "{EURASIP} Journal on Advances in Signal Processing", volume = "", editor = "", number = "", publisher = "", note = "doi:10.1155/2007/92953", url = "http://www2.compute.dtu.dk/pubdb/pubs/4875-full.html", abstract = "We survey the definitions and use of rank-revealing matrix decompositions in single-channel noise reduction algorithms for speech signals. Our algorithms are based on the rank-reduction paradigm and, in particular, signal subspace techniques. The focus is on practical working algorithms, using both diagonal (eigenvalue and singular value) decompositions and rank-revealing triangular decompositions ({ULV,} {URV,} {VSV,} {ULLV} and {ULLIV}). In addition we show how the subspace-based algorithms can be evaluated and compared by means of simple {FIR} filter interpretations. The algorithms are illustrated with working Matlab code and applications in speech processing." }