Speech enhancement using sub-band cross-correlation compensated Wiener filter combined with harmonic regeneration

An improved Wiener filtering method for reducing background noise added to speech in colored noise environments like car engine is proposed in this paper. This implementation uses the cross-correlartion between the speech and noise signals. The noise signal does not affect the speech signal uniformly over the whole spectrum. A nonlinear sub-band Bark scale frequency spacing approach is used to reduce colored noise. However, classic short-time noise reduction techniques, including Wiener filter, introduce harmonic distortion in enhanced speech because of the unreliability of estimators for small signal-to-noise ratios. To overcome this problem, we propose a method to regenerate the suppressed harmonics. Nonlinearity is used to regenerate the degraded harmonics of the distorted signal in an efficient way. Objective and subjective tests demonstrated the proposed technique can improve the perceptual quality of speeches.