Wavelet transform-based speech enhancement

This paper describes a speech enhancement system using a novel combination of a Fast Wavelet Transform structure, together with “Wiener filtering” in the wavelet domain. The specific application of interest is the enhancement of speech when a cellular phone is used within a moving vehicle. Subjective tests carried out using speech with additive vehicle noise at a signal-to-noise ratio of 10 dB indicate that the Wavelet transform-based Wiener filtering approach works well. In particular, the technique was compared to several other common enhancement methods such as thresholding applied in the wavelet domain, FFT-based Wiener filtering, and spectral subtraction, and was found to outperform these other techniques.