[ART] Music "Lower" if player enters area

[Amnesiaplayer]

I need to make it that if a people go into a certain area, the music's volume is getting lower, like form 1, it goes to 0.5 or something like that, and when he goes out of that area, the music will be back at 1.
Creating a snow map, and it can be much more realistic if the sound's turning lower if you're inside a building.
I don't really know how these If scripts work..
The only thing I can mind is
IF( blabla entitycollideare or idk, but is it possible to make the music's volume lower ??