Game uses OGG vorbis but the files are obfuscated.
This is the audio engine it uses. http://sol.gfxile.net/soloud/
Samples as always, are provided.
https://mega.nz/#!NzI32YoD!T5wMaj3oxv49VEPVXsiGII-WqY9viWjAEejaOZ6KiTg
Update addendum:
If you mess around with the "Settings.cfg" file you can get access to some in-built "modding" tools. But I couldn't find anything to render the audio as a PCM WAV file or even as an .ogg without the obfuscation.