Estimation of missing LSF parameters using Gaussian mixture models

Speech transmission over packet networks has to cope with packet delays and packet losses. When a packet loss occurs the missing information must be estimated. We focus on restoring the spectral parameters of a speech coder. A novel approach to estimating missing line spectral frequency (LSF) parameters using Gaussian mixture models (GMM) is proposed. We present the estimation algorithm and study its performance when one or several LSF parameters are lost. We show that a GMM of a relatively low order is sufficient to achieve a substantial improvement in the parameter SNR. Therefore, the new estimation procedure requires much less memory than histogram based estimation methods.