Subband modulator Kalman filtering for single channel speech enhancement

This paper presents a single channel speech enhancement technique based on sub-band modulator Kalman filtering for laryngeal (normal) and a laryngeal (Esophageal speech) speech signals. The noisy speech signal is decomposed into sub-bands and subsequently each sub-band is demodulated into its modulator and carrier components. Kalman filter is applied to modulators of all sub-bands without altering the carriers. Performance of the proposed system has been validated by Mean Opinion Score (MOS) for laryngeal and Harmonic to Noise Ratio (HNR) for a laryngeal speech. An improvement of 20% has been observed in MOS over sub-band Kalman filtering for laryngeal speech, while 3 to 4 dB enhancement in HNR has been observed for a laryngeal speech over the full-band Kalman filtering.