An Approach for Voiced/Unvoiced Decision of Colored Noise-Corrupted Speech

A two-step algorithm for the voiced/unvoiced (V/UV) decision of colored noise-corrupted speech is presented in this paper. An effective noise-whitening process is first applied to the noisy speech to combat the adverse effect of colored noise. Then, a harmonicity measure is proposed which is derived from the LP residual of the pre-whitened speech. Integrating root-mean-square energy and zero-crossing rate, another composite measure is introduced. In the first step, signal-dependent initial-thresholds (SDITs) for both the measures which are capable of highlighting distinctive attributes of voiced and unvoiced frames, are determined analyzing their statistical properties. In the second step, based on the SDITs, a bi-feature logical target function is formulated to attain a preliminary score of V/UV decision. Additional voicing criteria are developed to conquer the artifacts that may exist due to the overlapping between decision regions. Simulation results demonstrate that the proposed algorithm yields superior performance in comparison with some of the existing V/UV decision schemes in the same interfering colored noise scenario.