Method and device for detecting voice activity
AssigneeMatra Nortel Communications
InventorsStéphane Lubiarz, Edouard Hinard, François Capman, Philip Lockwood
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Abstract
The invention concerns a method for detecting voice activity in a digital speech signal, in at least a frequency band, for example by means of a detecting automaton whereof the status is controlled on the basis of an energy analysis of the signal. The control of said automaton, or more generally the determination of voice activity, comprises a comparison, in the frequency band, of two different versions of the speech signal one of which at least is a noise-corrected version.
Claims30
Method for detecting voice activity in a digital speech signal in at least one frequency band, wherein the voice activity is detected on the basis of an analysis comprising the step of comparing two different versions of the speech signal, wherein the two different versions of the speech signal are two versions denoised by non-linear spectral subtraction, wherein a first of the two versions is denoised in such a way as not to be less, in the spectral domain, than a first fraction of a long-term estimate representative of a noise component included in the speech signal, and the second of the two versions is denoised in such a way as not to be less, in the spectral domain, than a second fraction of said long-term estimate, smaller than said first fraction.
Device for detecting voice activity in a speech signal, comprising signal processing means for analyzing the speech signal in at least one frequency band, wherein the processing means comprise:
- first non-linear spectral subtraction means to provide a first version of the speech signal as a denoised version which is not less, in the spectral domain, than a first fraction of a long-term estimate representative of a noise component included in the speech signal;
- second non-linear spectral subtraction means to provide a second version of the speech signal as a denoised version which is not less, in the spectral domain, than a second fraction of said long-term estimate, said second fraction being smaller than said first fraction;
- and
- means for comparing the first and second versions of the speech signal.
A computer program product, loadable into a memory associated with a processor, and comprising portions of code for execution by the processor to detect voice activity in an input digital speech signal in at least one frequency band, whereby the voice activity is detected on the basis of an analysis comprising the step of comparing two different versions of the speech signal, wherein the two different versions of the speech signal are two versions denoised by non-linear spectral subtraction, wherein a first of the two versions is denoised in such a way as not to be less, in the spectral domain, than a first fraction of a long-term estimate representative of a noise component included in the speech signal, and the second of the two versions is denoised in such a way as not to be less, in the spectral domain, than a second fraction of said long-term estimate, smaller than said first fraction.
Dependencies are inferred from the claim text.