Firefighters may be snuffing blazes with deep-toned sound, if a new device invented by two engineering students in Fairfax, Virginia, catches on.

Viet Tran and Seth Robertson's new fire extinguisher looks a little like a conventional one, but instead of a compressed air tank spewing out chemicals, theirs has a loudspeaker the size of subwoofer drumming out sound waves.
http://www.kulr8.com/story/28673486/new-fire-extinguisher-uses-sound-waves-to-put-out-flames