Obstruction/Occlusion is currently supported only through code calls. We don't provide any geometry-based analysis yet. You can check the Wwise SDK documentation ([Wwise]\SDK\Help) for SetObjectObstructionAndOcclusion as a basis. There is numerous ways to integrate this, some more complex (and costly) than others.
A quick and dirty way would simply be to use the raytracing functionality between all sound emitters of importance and the listener. If there is a hit, you'll need to determine what you did hit. Is it a wall splitting 2 rooms? A simple object? If a wall, then you could assume occlusion and either hardcode an occlusion level or set it based on the material. If it is not a wall, then set the obstruction level.
There are entire papers based on sound propagation :) Each game has its own needs and (more importantly) its limit in terms of CPU and memory it wants to spend on that particular problem. So we provide the basic hook to feed obstruction/occlusion, but the actual geometry analysis is left for the game programmer.