If you want to extract Xenophonia's sounds, you can either copy the audio.dat file, or run extract it and copy the resulting "voice" folder instead. But like I said, you can use extract_audio.bat to extract other files as well, but you need to edit it so that it reads, e.g.
Code:
@ECHO OFF
.\xidx.exe -x data\sounds\SFX
instead of
Code:
@ECHO OFF
.\xidx.exe -x data\sounds\audio
and then it will extract SFX.dat/idx instead of audio.dat/idx. SFX seems to be the only file that actually contains anything, so extract it.