Adding sound to ppt

Hello,

I have a late 2009 iMac running Lion. I had to create a storyboard for school using PowerPoint. I had to add audio files to at least two slides. Although I was able to create them and insert them when I tried saving the PowerPoint it gave me a warning that some aspects (the sound) would not be saved. When I checked the compatibility report it suggested I saved the ppt in a different format. However, none of the formats have successfully kept the sound. I can hear the sound but when my instructor or team mates in class open it there is no sound. I have tried everything. I used keynote them imported it to ppt. I tried office for Mac 2008, I even purchased office for Mac 2011 to no avail. Please help. I have tried recording the voice with GarageBand, QuickTime and audacity. Same results I can hear the sound but no one else