Invention to Shut People Up

Kazutake Kurihara of the National Institute of Advanced Industrial Science and Technology, and Koji Tskada of Ochanomize have created a “SpeechJammer” gun! It can silence people more then 30 meters away. The device records its targets speech and fires their words back at them with a 0.2-second delay which affects the brains cognitive process and causes speakers to stutter until they get silenced completely. They say “In general, human speech is jammed by giving back to the speakers their own utterances at a delay of a few hundred milliseconds. This effect can disturb people without any physical discomfort, and disappears immediately by stopping speaking." They say it could be used to silence people in public libraries that are being to loud.
http://www.foxnews.com/scitech/2012/03/02/japan-invents-speech-jamming-gun-that-silences-people-mid-sentence/