I'm not sure it supports audio, but you could try motion:
http://www.lavrsen.dk/foswiki/bin/vi...ionFeatureList
Theoretically, you could get it to launch another audio/video streaming/recording app once motion was detected...
One thing to point out though...
It may be illegal in your jurisdiction to record audio (or audio with video) without proper consent. You should check ypur local laws, and/or consult an attorney before attempting to record both audio and video, and determine what steps would make it allowable, if permitted.