EUROSPEECH 2001 Scandinavia
7th European Conference on Speech Communication and Technology

Aalborg, Denmark
September 3-7, 2001


Enhancement of Speech Using Bark-Scaled Wavelet Packet Decomposition

Israel Cohen

Lamar Signal Processing Ltd., Israel

In this paper, we propose a speech enhancement system, which integrates a bark-scaled wavelet packet decomposition (BS-WPD), a soft-decision gain modification and a "magnitude" decision-directed estimation technique. The BS-WPD provides an overcomplete auditory representation, having a higher frequency resolution than the critical band decomposition. Speech is estimated by Wiener filtering in the wavelet packet domain, modified by the signal presence probability. We introduce a "magnitude" decision-directed estimator for the variance of speech, which is closely related to the decision-directed estimator of Ephraim and Malah. This estimator achieves, in the established process, a better tradeoff between noise reduction and signal distortion. The proposed enhancement algorithm is tested with various noise types, and compared to a conventional log-spectral amplitude estimator. We show that noise can be further suppressed, while preserving its natural structure and the intelligibility and quality of the speech components.

Full Paper

Bibliographic reference.  Cohen, Israel (2001): "Enhancement of speech using bark-scaled wavelet packet decomposition", In EUROSPEECH-2001, 1933-1936.