Already have such examples on my blog, but I'm still busy moving the articles.
You'll need to add some more decisions to your advanced conditional action. The idea is that you create a user variable that will be toggled from 0 to 1 after leaving that slide. First time on Enter the variable will still be 0, you can check it and play the audio. You do not tell which version you use. If you us 6, you can use the Play Audio statement (which is new), if you are on a previous version, attach the audio to an object like a Highlight box or a drawing object (can be made invisible by making alpha for fill 0, and having no stroke). And hide that object when the variable is 1.
Lilybiri
