A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
Easiest way is to insert as a transition sound and then insert another on slide 6. They will need to be wav files though
Alternatively set the first sound to Play Automatically and in the animation pane Double click the first sound entry and in Effects set "Stop playing" to after 5 slides.
Microsoft® MVP PowerPoint® since 2007.
Web Page: PowerPoint Alchemy Hints and Tips