Patent ID: 8639504

Claim:
One or more computer-readable storage memory devices comprising processor-executable instructions which, responsive to execution by at least one processor, are configured to enable a device to: receive an input signal representing a property of speech; quantize the input signal effective to generate a quantized output signal; prior to said quantization, supply a version of the input signal to a first noise shaping filter having a first set of filter coefficients effective to generate a first filtered signal based on that version of the input signal and the first set of filter coefficients; following said quantization, supply a version of the quantized output signal to a second noise shaping filter having a second set of filter coefficients different than said first set effective to generate a second filtered signal based on that version of the quantized output signal and the second set of filter coefficients; perform a noise shaping operation to control a frequency spectrum of a noise effect in the quantized output signal caused by said quantization, wherein the noise shaping operation is performed based on both the first and second filtered signals; and transmit the quantized output signal in an encoded signal, the quantized output signal based, at least in part, on the first filtered signal and the second filtered signal.