I think you can use an [AudioVolume][1] actor whose settings you can modify based on its height in the world. One way to do that would be to create another actor placed in the level which references this AudioVolume actor, binds to its overlap event, and makes any necessary modifications based on its height. For example if you wanted to modify the InteriorVolume property you could do this:
If current height (AudioVolume’s Z) is 300 and MaxHeight is 600, then you would be setting the volume to 0.5
Not sure if this answers the specific thing you’re trying to do but hope this helps.