PowerPoint 2011 for Mac enables you to work with various types of sound files such as MP3, WMA, or WAV. However, inserted sounds are always embedded within your presentation, which is different from the default behavior in previous versions of PowerPoint which always linked sound files rather than embedding them. This has a plus side since you now no longer have to worry about linked files getting misplaced or lost. On the flip side, this can balloon file sizes. Having said that, it is still a good practice to keep your sound files in the same folder in which you save your PowerPoint 2011 presentation — even before you insert them.