Chat Gem (Pandemonium Fortress Conspiracy Edition)

I was in A4 fortress, solo online game (LoD, non-ladder SC, fyi), when I heard a ring drop, or the chat gem.

No other players. Thought I had dropped a ring somehow (but wasnt in inv). Nothing at all on Ground. I thought I was hearing things, so didnt think much of it until I heard it *again* .

Running around like an idiot looking for the sound, it seemed like it made that sound every time I went under one of the supporting arches. Yes, but it is more specific than that, it is a specific line

There is an invisible line seperating the stash/cain/

Tyrael side, and everything else on the other side. If you move from the stash side, across this invisible line, it is about half a second (probably less) before you hear the sound.

It doesn't work going the other way. It doesn't work if you only stop on a certain place on the floor. Just that one-way line trigger. It is repeatable if you go back to stash side and walk over it again.

Likely this is just some sound trigger for ambience, as if

Halbu is making something forge-y... but...

...I can't help but wonder, since it sounds a bit similar to the chat gem...

Here's what i'm talking about. Please excuse my shoddy image-fu. When crossing from blue shaded area over the red line, the sound triggers.