Multi-channel speech enhancement in a car environment using Wiener filtering and spectral subtraction

1 MULTI-CHANNEL SPEECH ENHANCEMENT IN A CAR ENVIRONMENT USING WIENER FILTERING AND SPECTRAL SUBTRACTION Joerg Meyer and Klaus Uwe Simmer University of Bremen, FB{1, Dept. of Telecommunications P.O. Box 33 04 40, D-28334 Bremen, Germany, Fax: +(49)-421/218-3341, e-mail: [email protected] ABSTRACT This paper presents a multichannel-algorithm for speech enhancement for hands{free telephone systems in cars. This new algorithm takes advantage of the special noise characteristics in fast driving cars. The incoherence of the noise allows to use adaptive Wiener ltering in the frequencies above a theoretically determined frequency. Below this frequency a smoothed spectral subtraction (SSS) is used to get an improved noise suppression. The algorithm yields better results in noise reduction with signi cantly less distortions and arti cial noise than spectral subtraction or Wiener ltering alone.