Patent ID: 8473284

Claim:
A voice encoder comprising: a quantization selection unit generating a quantization selection signal to represent a result of a selecting, before quantizing a line spectral frequency (LSF) of a current frame of an input signal, one of a first LSF quantization unit and a second LSF quantization unit for the quantizing of the LSF of the current frame, wherein the selecting is based on analysis by the quantization selection unit of a generated synthesized voice signal of a previous frame of the input signal; and a quantization unit extracting a linear prediction coding (LPC) coefficient from the current frame of the input signal, converting the extracted LPC coefficient into the LSF of the current frame, quantizing the LSF of the current frame with the selected one of the first LSF quantization unit using a first predictor and the second LSF quantization unit using a second predictor, the second predictor being different from the first predictor, based on the quantization selection signal, and converting the quantized LSF into a quantized LPC coefficient.