Link: http://www.wired.com/underwire/2012/03/japanese-speech-jamming-gun/?intcid=story_ribbon
Two Japanese researchers recently introduced a prototype for a device they call a SpeechJammer [size=15pt]that can literally “jam” someone’s voice — effectively stopping them from talking[/size]. Now they’ve released a video of the device in action.

“We have to establish and obey rules for proper turn-taking,” write Kazutaka Kurihara and Koji Tsukada in their article on the SpeechJammer (PDF). “However, some people tend to lengthen their turns or deliberately disrupt other people when it is their turn … rather than achieve more fruitful discussions.”

The design of the SpeechJammer is deceptively simple. It consists of a direction-sensitive microphone and a direction-sensitive speaker, a motherboard, a distance sensor and some relatively straightforward code. The concept is simple, too — it operates on the well-studied principle of delayed auditory feedback. By playing someone’s voice back to them, at a slight delay (around 200 milliseconds), you can jam a person’s speech.

Video:
[flash=200,200]
https://www.youtube.com/watch?v=USDI3wnTZZg[/flash]