Estimating the noncircularity of latent components within complex-valued subband mixtures with applications to speech processing

This paper describes an approach that estimates the circularity coefficients of multiple underlying components within complex subbands of an additive mixture of voiced speech and noise via the strong uncorrelating transform (SUT). For the SUT to be effective, the latent source signals must have unique nonzero circularity coefficients; this requirement is satisfied by using narrow filters to impose a degree of noncircularity upon what would typically be circular noise. The circularity coefficient estimates are then used for voice activity detection, pitch tracking, and enhancement.