Subjective evaluation of LSF quantization in conventional and warped LP based audio coding

The objective of this study is to evaluate subjective quality of spectral envelope quantization in audio coding. In this paper, the spectral envelope is modeled using Linear Prediction (LP) and Warped Linear Prediction (WLP). The advantage of WLP compared to LP is that the frequency resolution of analysis can be modified so that it follows perceptual frequency scale, like the Bark- or ERB-scale. The coefficients in both cases are transformed into Line Spectral Frequency (LSF) parameters and quantized. The quantization of these parameters is studied and the subjective and objective qualities are compared.