Patent ID: 8069040

Claim:
A method for signal processing, said method comprising performing each of the following acts within a device that is configured to process speech signals: encoding a first frame and a second frame of a speech signal to produce corresponding first and second vectors, wherein the first vector describes a spectral envelope of the speech signal during the first frame and the second vector describes a spectral envelope of the speech signal during the second frame; generating a first quantized vector, said generating including quantizing a third vector that is based on the first vector; dequantizing the first quantized vector to produce a first dequantized vector; calculating a quantization error of the first quantized vector, wherein the quantization error indicates a difference between the first dequantized vector and one among the first and third vectors; calculating a fourth vector, said calculating of the fourth vector including adding a scaled version of the quantization error to the second vector; and quantizing the fourth vector, wherein the third vector describes a spectral envelope of the speech signal during the first frame and the fourth vector describes a spectral envelope of the speech signal during the second frame.