A packet loss recovery of G.729 speech under severe packet loss condition

In a VoIP application, packet losses degrade speech quality. Especially, IP network under a large-scale disaster should cause severe packet losses. We investigate influence of parameter loss to speech quality using G.729. And we investigated an effect of packet loss concealment method using redundant G.729 parameters. As compared with “repetition” method, the proposed method could improve speech quality. We also propose a bitrate reduction method by sending bit flip position instead of codebook index.