An analysis of interleavers for robust speech recognition in burst-like packet loss

An analysis into the effect of packet loss shows that a speech recogniser is able to tolerate large percentages of packet loss provided that burst lengths are relatively small. This leads to the analysis of three types of interleaver for distributing long bursts of packet loss into a series of shorter bursts. Cubic interpolation is then used to estimate lost feature vectors. Experimental results are presented for a range of channel conditions and demonstrate that interleaving offers significant increases in recognition accuracy under burst-like packet loss. Of the interleavers tested, decorrelated interleaving gives superior recognition performance and has the lowest delay. For example at a packet loss rate of 50% and average burst length 20 packets (40 vectors or 400ms) performance is increased from 49.6% with no compensation to 86% with interleaving and cubic interpolation.