I just did what you asked.
I always keep a copy of an "untouched" mod when I experiment with sounds.
all the text files remained how I downloaded them. my sounds is the same thing I have had since this mod was made (teutonic)
here is what happened:
I extracted all the files successfully to exe file sends them. /data/sounds/data/sounds/(wtv..)
i moved the 3 files, music, sfx and voice out of there and place them in /data/sounds
I deleted all events, voice, sfx and music idx & dat files.
ran the game and crash! the music that is rebuilt is from vanilla with all the SFX stuff still missing!
the second time I left them all where they were, meaning where they were first extracted too.
still the same result.
events was about 1800kb and other files were 1kbs.