A pair of Japanese researchers have created a hand held gun like device that will stop people from talking. It’s essentially a painless real life version of a mute button that someone finds on their remote control.
The principle behind this device is quite interesting. Known as the Speech Jammer, this unit works on the concept of of DAF or Delayed Auditory Feedback. Essentially the Speech Jammer is a unidirectional device which when activated, will identify voice conversations through its microphones. At this point, it will take in the conversation and replay it back to the speaker with a delay of 0.2 seconds. When the speaker hears his own voice coming back at him, he will begin to stutter and ultimately stop speaking.
Known as Delayed Auditory Feedback or DAF for short, scientists believe that the human mind needs to hear its own speech once as it leaves the mouth, but to hear it twice such as in the case of the Speech Jammer, causes confusion and ultimately vocal submission. The device causes no pain whatsoever nor does it have any lingering effects. Once the device has been deactivated, the user will be able to speak properly again. To give you an idea of just how this device works, think of a time that you may have used a voice over IP application such as Skype. If you don’t have a good network connection, there is a chance that you may have experienced feedback by way of your own voice being echoed. This is similar to how the Speech Jammer works.
The researchers behind this invention are Koji Tsukada and Kazutaka Kurihara and according to them, they could see this device being deployed in a variety of quiet settings such as a library or classroom. The active range for the unit is 100 feet or 30 meters.