What sound effects library do the 2000-2002 games use?

[Xazo-Tak]

The sound design in Avernum 3 is my favourite in any game, so I'm curious as to where the sound effects come from. I've searched on my own, to no avail.

 

I have heard the cave dripping sound effect in a lot of things outside Avernum, so I'm guessing it's a royalty-free sound effect.

I'm also guessing that a limited library (such as a sound effects disc) was used for the original Avernum trilogy because of how unusual some of the sound effect choices were. Particularly the lightning spell.

But finding an old sound effects library would be nearly impossible unless you knew were to look. Search results when you look up anything sound-effects related are flooded with random junk because of the all-too-vast number of amateur sound effect producers.