US 6,983,242 B1
Method for robust classification in speech coding
Jes Thyssen, Laguna Niguel, Calif. (US)
Assigned to Mindspeed Technologies, Inc., Newport Beach, Calif. (US)
Filed on Aug. 21, 2000, as Appl. No. 9/643,017.
Int. Cl. G10L 11/00 (2006.01); G10L 21/02 (2006.01)
U.S. Cl. 704—208 8 Claims
OG exemplary drawing
 
1. A method for classifying a speech signal having a background noise portion with a background noise level, the method comprising the steps of:
extracting a parameter from the speech signal;
estimating a noise component of the parameter;
removing the noise component from the parameter to generate a noise-free parameter;
selecting a pre-determined threshold, wherein the step of selecting said pre-determined threshold is unaffected by said background noise level;
comparing the noise-free parameter with a said pre-determined threshold; and
associating the speech signal with a class in response to the comparing step;
wherein the extracting step extracts a plurality of parameters and the steps of estimating, removing selecting, comparing and associating are performed for each of the plurality of parameters, wherein the plurality of parameters include a spectral tilt parameter, a pitch correlation parameter and an absolute maximum parameter, and wherein said spectral tilt parameter is weighted to generate a noise-free spectral tilt parameter during the step of removing, said pitch correlation parameter is weighted to generate a noise-free pitch correlation parameter during the step of removing and said absolute maximum parameter is weighted to generate a noise-free absolute maximum parameter during the step of removing.