PowerPoint Tutorial: Adding Sound to a PowerPoint Show
http://www.presentersuniversity.com/courses_tutorials_tutorials_powerpoint.php

Presenters University
2001

Abstract:

There are many sites where you can download or buy MIDI or Audio files on the web. Many of these sites offer illegal sound clips. Finding sound clips on the Web is very easy--simply do a search for sound clips, and you'll be directed to many different web pages. Just be sure that you can legally use these sound clips before putting them on your site.