Levels can have different reverb settings in different areas. A simple example of this is underwater versus outside of the water. Rather than having to create many different variations to a .wav file, reverb volumes can be designed directly in the Editor and can drastically change the way sound events are played back. Like AmbientVolumes, ReverbVolumes are attached to area shapes or boxes. They can be attached to the same area shape/box as an AmbientVolume already is, and will affect that AmbientVolume entity's sound events.