Shai Drori wrote
> ​We need something that converts them to a more archival file format, not
> just play them.​
Reaper will save your files into common audio file formats.

Also the mentioned VLC-Player can convert and save from format to 
another, although
I the procedure is a bit clumsy to use.

I found several AUD to WAV on-line converters by Googling. Wonder if you 
could use
one of those? Having said that, I myself am not very fond of on-line 
converters, where
you need to upload your files into who knows where.

Eero