Stopping music, spawning objects. Help.

[Romulator]

Try lowering the MaxDistance. Making it lower will decrease the radius in which the sound can be heard. I forget exactly how far away it equates to, so you may have to do a little bit of testing and changing to alter it.

Edit:
Have you also got the .ogg file(s) for the ambience_haunting.snt somewhere in your custom story directory (preferably your own)?

In terms of the scripting aspect, it should be the same as colliding with a normal script area, provided it is tall/thick/wide enough for the Player to not miss it. As such, you would use an AddEntityCollideCallback like the one above, and like Mudbill below me says, to use PlayGuiSound(); if it should be around the Player.

If it still does not work, recheck the names of your script areas.