Hey Jim,
Yes, please make sure you are on version 7.2.2 (Help > About). If you are, you should be able to drag and drop the audio file. Or, you can go into the Background Settings to add it that way (then, it will play across the entire cue with multiple pages).
https://support.mediashout.com/849951-Working-with-Audio-Files-in-MediaShout-7
Thanks,
-Ryan