The vomit utility converts a Cisco IP phone conversation into a wave file
that can be played with ordinary sound players. The phone conversation can
either be played directly from the network or from a tcpdump output file.
Vomit is also capable of inserting wavefiles into ongoing telephone
conversations. Vomit can be used as a network debugging tool, a speaker
phone, etc ...

WWW: http://www.monkey.org/~provos/vomit/