1. A system for applying feature-space maximum likelihood linear regression (fMLLR) to correlated features, the system comprising: a semi-tied covariance (STC) module capable of mapping the correlated features into an uncorrelated feature space; an fMLLR module capable of applying fMLLR in the uncorrelated feature space to obtain fMLLR transformed features; and a return module capable of mapping the fMLLR transformed features back to a correlated feature space.