Noise Cancellation
Noise cancellation generators for active noise control are a relatively modern innovation. A microphone is used to pick up the sound that is then analyzed by a computer; then, sound waves with opposite polarity (180° phase at all frequencies) are output through a speaker, causing destructive interference and cancelling much of the noise.
Read more about this topic: Soundproofing
Famous quotes containing the word noise:
“I’ve almost gained my heav’nly home; My spirit loudly sings;
The holy ones behold they come, I hear the noise of wings.
O come, angel band, Come and around me stand.
O bear me away on your snowy wings, To my immortal home.”
—T. Haskell, minister and hymn-writer. Published in Christian Harmony. “Angel Band,” l. 5-8.