Power Point Sound Issue

I did a presentation for my computer class and put sound effects in it, but 2 of the slides won't plays the sound the other 3 slides will. I downloaded the sound files from a website and I changed them from mp3 to wav. That didn't fix it either. I can hear the sounds on my computer, but when I emailed it the sounds wouldn't play on 2 of the slides. I was wondering if their is a folder I need to put these sound file in, so powerpoint will see them.