[Al Bloom]

Hey,
long time but I needed the same answer and figured it out..
I was initially just unticking ‘Export Video’ halfway down the export settings (where the only audio options are AAC, Dolby Digital and MPEG), but here’s how you do it to other formats:

Go to File>Export>Media, change the first box ‘Export Settings’>’Format’ – change that (my default was H.264) to WAV or whatever other audio format you want.
Peace, Al