Sixth European Conference on Speech Communication and Technology

Budapest, Hungary
September 5-9, 1999

Speech Enhancement Using Fourth-Order Cumulants and Time-Domain Optimal Filters

Elias Nemer (1), Rafik Goubran (2), Samy Mahmoud (2)

(1) Nortel Networks, Verdun, Quebec, Canada
(2) Systems & Computer Eng’g, Carleton University, Ottawa, Ontario, Canada

A new method for speech enhancement based on optimal filtering, subbands, and higher-order cumulants is proposed in this paper. The key idea is to use the 4th cumulant to estimate the parameters required for the enhancement fil-ters: It is shown that the kurtosis of noisy speech may be used to estimate the SNR and the probability of speech presence when speech is divided in narrow bands and mod-eled as a sinusoidal signal. The resulting algorithm is tested in typical mobile noise conditions and proves effective under such types as street, office and fan noises. Compared to the TIA IS-127 standard for noise reduction, the proposed algorithm is better at preserving the harmonic structure of the speech and results in overall more noise reduction in Gaussian-like conditions. However, this comes at the cost of slightly more noise artifact, mostly at very low SNR and non-Gaussian conditions.

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Acoustic Example

Bibliographic reference.  Nemer, Elias / Goubran, Rafik / Mahmoud, Samy (1999): "Speech enhancement using fourth-order cumulants and time-domain optimal filters", In EUROSPEECH'99, 2623-2626.