Audio controls in exhibits: can somebody *please* help

I've posted several times in the past while about this issue, but have still not received an answer that actually addresses my problem. I can see from the forums that quite a few other people have been having the same problem, but nobody has as yet posted a satisfactory answer, even though it is clear some people have managed to solve their issue.

To take my question back to its basics: can somebody please give me step-by-step instructions about how to add an audio file to an exhibit so that it displays a slider for users to control.