Can Geometry and Materials affect Sound Volume?

What you’re looking for is occlusion and obstruction, as well as early reflections management.
There’s nothing like it in UE4 at the moment, nor most game engines - the way it’s managed usually consists in placing reverb or obstruction volumes which may or may not be extracted from the geometry (it’s usually done manually).

There are a few projects to handle this sort of things automatically, such as Two Big Ears’s. I haven’t tried it personally, it’s in closed beta at the moment, but you can apply for it.