A quantizer according to an embodiment is configured to quantize a smoothed value of an input value (e.g., a vector of line spectral frequencies) to produce a corresponding output value, where the smoothed value is based on a scale factor and a quantization error of a previous output value....http://www.google.com/patents/US8069040?utm_source=gb-gplus-sharePatent US8069040 - Systems, methods, and apparatus for quantization of spectral envelope representation
