Predicting VQ Performance Bound for LSF Coding

For vector quantization (VQ) of speech line spectrum frequency (LSF) parameters, we experimentally determine a mapping function between the mean square error (MSE) measure and the perceptually motivated average spectral distortion (SD) measure. Using the mapping function, we estimate the minimum bits/vector required for transparent quantization of telephone-band and wide-band speech LSF parameters, respectively, as 22 bits/vector and 36 bits/vector, where the distribution of LSF vector is modeled as a Gaussian mixture model (GMM).