Hello,
I was not able to reproduce it in Forsaken Abbey nor Necropolis of Mirrors, but I found issue in Dead Tree Cave.
There is a few places in Taborea that have no ambient sound definied.
For example Dead Tree Cave has no ambient sound.
Only Sevaida Woods do.
The magic sound (I assume "Ooooo ..." you mentioned) is from Woods.
But, as of engine failure when you entered area with no ambient sound (Dead Tree Cave) it was never disabled and was losing handler, so could not be stopped anymore.
I possibly fixed it along with playing regular music in no-music zone. Was running a bit at current and new client and it feels fine.
It will be patched with next patch.
You will be surely able to notice that some areas in Taborea may feel more silent now, as of they will not duplicate previous ambient sounds. So if are defined as empty, they will stay empty.
Greetings