Try saving the sound file to the same folder with your presentation, then
insert it into the presentation.
I suspect the problem is the length of the path to the sound. Or if you're
previewing online clips, they're buried somewhere in your Temporary Internet
Files folder, and the path is either too long or the sound file is being
deleted when the TIF is emptied. If you right-click the sound in the clip
organizer pane, you can choose Properties. With an online clip, you'll see a
path like this: C:\Users\UserName\AppData\Local\Microsoft\Windows\Temporary
Internet Files\Content.IE5\87N1NCBP\MSj04378740000[1].wav That's a very
long path.