I once took a group of so called audiophiles and gouged their eyes out so that they had no visual reference to rely on, and then I led them around what they thought were a labyrinth of rooms and told them that some of the rooms had acoustic panels installed and some had none. In reality I was just leading them around in a circle in my two car garage, but you should have heard those suckers rave about how good a JVC surround sound receiver hooked with lamp cord to a pair of JBLs from Crutchfield sounded when they thought that they were in a treated room.
Oh, and I conduct tests such as these all the time. It's really no big deal.