From inside these two minimal structures comes a constant quiet drone of exhalation and small motors. One an exact clone of the other, each blows a soft breath continuously out of an aluminum hole in its face. The moving air is fed to the holes by a ribbed white tube descending into the depths of each structure, like an esophagus. From behind each, a cord forms a tail that leads to the wall, and as a pair, their plugs fill a wall socket.