Industrial Noise indoors and outdoors with Noise Transmission. The SoundPLAN industrial noise modeling is unique. All questions of frequency dependant noise can be simulated whether it is purely an indoor problem, a receiver outside that needs to be assessed for outside sources, or a complex problem with the source inside an industrial building and a receiver on another building. The simulations inside industrial buildings are completely integrated with the transmission through the outer walls and the propagation into the environment.