i don't know exactly what you need to do to claim that licensing for audio files, as i've mainly been concerned about photos. but the creative commons website has a very easily understood explanation of the variations on the CC license that make sense for different applications; there's even a step by step decision-maker that will help you decide which license best fits your situation. they've got sections of the site broken out very obviously for different types of media.

www.creativecommons.org

somewhat-relatedly, there was an extensive piece in Wird magazine a while back about how folks are releasing audio under creative commons licenses - there was even a CD full of tracks from high profile artists that were released under CC:

wired-vig.wired.com/wired/archive/12.11/