I finally tested out adding an audio recording file to my public notes site, and it worked! I had to move it to the public folder in my notes, export the notes to my public quartz project folder, then generate the site based on the public quartz folder. And it worked!
- Now to see if the audio files include some exif data in them that might unwittingly expose my location data (as photos from my phone would, if directly posted prior to removing that metadata from them)