If you have added it through Insert > Movies and Sounds > Sound from file:
Select Effect Options, and on the Effects tab, click the radio button beside
Stop Playing after XXX slides. Put 999 in the box so the track will play
throughout all your slides, even if you go back and forth among slides.
For more information, check this out:
"Play sounds across multiple slides (A WAV runs through it)"
http://www.rdpslides.com/pptfaq/FAQ00047.htm
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Shawn Toh (tohlz)
Microsoft Most Valuable Professional (MVP PowerPoint)
Site Updated: Sep 01, 2006
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