Noise suppression with high speech quality based on weighted noise estimation and MMSE STSA

• Published in: Electronics & communications in Japan. Part 3, Fundamental electronic science Fundamental electronic science, 2006-02, Vol.89 (2), p.43-53
• Main Authors: Kato, Masanori, Sugiyama, Akihiko, Serizawa, Masahiro
• Format: Article
• Language: English
• Subjects: noise estimation; noise suppression; short-time amplitude spectrum; speech emphasis
• ISSN: 1042-0967; 1520-6440
• DOI: 10.1002/ecjc.20145

This paper proposes a high speech quality noise suppression method based on weighted noise estimation and MMSE STSA. The proposed method continuously updates the noise estimate, using weighted noisy speech according to the estimated speech‐to‐noise ratio. In order to fully utilize the improvement offered by noise estimation, the spectral gain is corrected according to the estimated speech‐to‐noise ratio. By using accurate noise estimation, more accurate SNR than in the conventional method is obtained, which helps to reduce distortion in the enhanced speech. In subjective speech quality evaluations, the five‐stage MOS was improved by 0.35 and 0.40 at the maximum, respectively, for the cases in which the speech was encoded and was not encoded after noise suppression. The improved version, which was developed on the basis of the proposed noise suppressor, satisfies all 3GPP minimum requirements for speech quality and has been installed in a commercially available model. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 89(2): 43–53, 2006; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecjc.20145