No version of PowerPoint has the inbuilt ability to do this. You will have to
use an audio editor to add the fade before you insert. Audacity is good and
free

Signature
Amazing PPT Hints, Tips and Tutorials
http://www.PPTAlchemy.co.uk
http://www.technologytrish.co.uk
email john AT technologytrish.co.uk
> Using Power Point 2003
>
> I have inserted a sound file that plays over the first 10 slides. Is there
> a way to fade out the sound at the end rather than having it just abruptly
> stop after 10 slides?