Back in 1957, author Arthur C. Clarke (of “2001: A Space Odyssey” fame) published a fictional compilation of shaggy-dog stories told in the White Hart pub by a henpecked college professor. The first of these “Tales from the White Hart” is the recollection of a lab technician named Fenton who succeeded in building a machine (the Fenton Silencer) that can absorb all of the sound in a room. The machine consists of a microphone that picks up sound, the requisite hodgepodge of electronic gadgetry and a loudspeaker that is driven precisely backwards from the soundwave. In this way, the sound energy in the room is completely absorbed and stored as electrical energy in the machine. One of Fenton’s college friends borrows the device for a harmless prank and, well, I bet your library has a copy of the book in the stacks.
The Fenton Silencer was one of the public’s first encounters with the concept of Active Noise Control. The story foretold of the day when electronic silencing would be commonly used to control unwanted noise.