The idea of noise cancelling has been around for a while, in fact it dates back to the 1930s. Since 1988, we have been able to buy progressively better noise cancelling headphones. Now in 2008, we are looking at a new technology which if successful, would develop to such an extent that by 2050 it would be around us everywhere. In fact, we would move from “surround sound” to “surrounded by no sound!” whenever we wanted to.
Selwyn Wright, Audio Researcher and Engineer at the University of Huddersfield in Yorkshire, UK has filed a patent called “Active noise control system in unrestricted space” for the Electronic Controlled Acoustic Shadow System (ECASS), or simply put the “silence machine”.
The concept is simple. All sound is transmitted by waves. Take a sound like the drone of a Jet engine, just reverse the sound wave, and play it back. The two waves cancel each other out and the result is nothing! No sound.
Cancelling sound in a headphone speaker cup is easy. In a room or open space it is much more difficult because of the furniture and carpet and other things that sound can bounce around off. You would need a computer with truly massive processing power to handle all those variables. With Selwyn’s current system, you can only mute out steady predictible noises like a tone while leaving everything else audible. However, more sophisticated versions of the technology are on the way. Soon you will be able to create quiet zones around your house, or in a garden. Residential areas around factories will benefit from this, as will highways and motorways.
Silence machines capable of blocking other types of sound, such as music, snoring, and human speech, were expected to be available around mid 2006 although I don’t see evidence of that yet. But it sounds like it’s on the way. There will probably come a time when you can zap a person into silence if you don’t want to hear what they have to say. Hmm, I wonder where that can be used? Stay tuned.