EsounD, the Enlightened Sound Daemon, is a server process that mixes several audio streams for playback by a single audio device. For example, if you're listening to music on a CD and you receive a sound-related event from ICQ, the two applications won't have to queue for the use of your sound card.

Install esound if you'd like to let sound applications share your audio device. You'll also need to install the audiofile package.