Restoration of instantaneous amplitude and phase using Kalman filter for speech enhancement

This paper proposes a restoration scheme for the instantaneous amplitudes and phases in sub-bands by using a Kalman filter with linear prediction (LP). A few important studies have already proved that phase spectrum on the short term Fourier transform plays an important role in speech enhancement. Thus, the proposed scheme concentrates on restoring of both the instantaneous amplitudes and phases simultaneously. In this scheme, the Kalman filter is used for both instantaneous amplitudes and phases in the sub-band representation to remove the effect of noise. Thus, it can sufficiently reduce the noise effects in both. Simulations were carried out in various noisy environments to evaluate the effectiveness of the proposed scheme. The signal to error ratio (SER), perceptual evaluation of speech quality (PESQ), and SNR loss were used as objective measures. Results showed that the proposed scheme can effectively improve these objective measures more than conventional methods.