1. A method for performing packet loss concealment in a packet-based speech communication system, the method comprising the steps of: receiving a sequence of one or more speech packets each comprising a set of speech parameters representative of speech data; identifying a failure to receive a lost speech packet comprising a set of speech parameters representative of speech data subsequent to the speech data represented by said sets of speech parameters comprised in said received sequence of one or more speech packets; determining a set of replacement speech parameters based on said sets of speech parameters comprised in said received sequence of one or more speech packets and further based on a statistical model, the statistical model comprising data identifying speech data represented by said set of replacement speech parameters as being likely to follow said speech data represented by said sets of speech parameters comprised in said received sequence of one or more speech packets; generating speech data for each speech packet in said received sequence of one or more speech packets based on said set of speech parameters comprised therein; and generating speech data for said lost speech packet based on said determined set of replacement speech parameters.