You can either record it on your PC or within the app. If you are interested in the PC option let me know, but I'll recommend you try the in-app recording first. In this case, you don't need to enter anything in your spreadsheet. Just transfer the text to the app.
Once you have your deck in the app, you can add sound. From the study screen, tap the bottom right icon to see the list of cards. Tap a card, scroll down to where you see "Sound 1" / "Sound 2", tap the appropriate side, and return your text. The downsides to this method is 1) it requires a bit of scrolling and tapping to record each sound and 2) you can't see your text as you record. I need to improve both of these issues. Give it a try though.
If you do the PC option, you just need to use a recording program to record sound clips, then you follow the instructions in my Excel documentation to put it all together.
http://orangeorapple.com/Flashcards/Flashcards%20Deluxe%20-%20Import%20Format.xlsLet me know if you have any problems.