US 6,477,489 B1Granted

Method for suppressing noise in a digital speech signal

AssigneeMatra Nortel Communications

InventorsPhilip Lockwood, Stéphane Lubiarz

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Abstract

A spectral subtraction is effected including: a first subtraction step in which overestimates of the spectral component of the noise are taken into account, to obtain spectral components of a first noise-suppressed signal; the computation of a masking curve by applying an auditory perception model on the basis of the spectral components of the first noise-suppressed signal; and a second subtraction step in which a respective quantity depending on parameters including a difference between the overestimate of the corresponding spectral component of the noise and the computed masking curve is subtracted from each spectral component of the speech signal in the frame. The result of the spectral subtraction is transformed into the time domain to construct a noise-suppressed speech signal.

Claims21

Dependent claims

Method of suppressing noise in a digital speech signal processed by successive frames, comprising the steps of:

computing spectral components of the speech signal of each frame;
computing, for each frame, overestimates of spectral components of noise included in the speech signal;
and
performing a spectral subtraction including
a first subtraction step in which a respective first quantity dependent on parameters including the overestimate of a corresponding spectral component of the noise for said frame is subtracted from each spectral component of the speech signal of the frame, to obtain spectral components of a first noise-suppressed signal;
computing a masking curve by applying an auditory perception model on the basis of the spectral components of the first noise-suppressed signal;
comparing the overestimates of the spectral components of the noise for the frame to the computed masking curve;
and
a second subtraction step in which a respective second quantity depending on parameters including a difference between the overestimate of the corresponding spectral component of the noise and the computed masking curve is subtracted from each spectral component of the speech signal of the frame.

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