Mumble has very low latency combined with good sound quality; it uses CELT and Speex, not just the voice compression technology, but also the voice pre-processing to remove noise and improve clarity. Mumble also has positional audio for supported games, meaning the other players' voice will come from the direction their character is in game.
TeamSpeak 3's voice quality is truly revolutionary. Featuring completely new codecs, automatic microphone adjustment, advanced noise reduction and echo cancellation, TeamSpeak 3 offers only the highest quality in voice communication.