You are very welcome.
I've heard that there are some free converts available on the web, but am
unfamiliar with them. Word of caution, since MP3s are highly compressed
sound files and WAVs are not, the converted file in WAV format will be huge.
Consequently, the PPT with the WAV embedded will be huge.
Files that are large are more susceptible to corruption, so as you build the
presentation, back-up often.
Good luck and have a Merry Christmas,
Bill D.