Packet loss concealment of VoIP under severe loss conditions

This paper describes an outline of a project for developing a VoIP codec that can be used under a very severe communication environment where half of the packets drop. The codec is based on G.729 CS-ACELP, and a packet loss concealment (PLC) methods with redundant information will be used for enhancing speech quality. The result of a preliminary experiment for assessing importance of G.729 parameters is presented, where we found that parameters related to spectral shape and gain were relatively important.