Every Teacher Wants One :-)

Coolest invention ever!

Ever since humans first invented guns, they've been inventing new uses for them. Some shoot bullets; others shoot lasers. But a strange and unsettling new gun being developed by Japanese researchers shoots sound waves in an effort to disrupt and silence anyone who dares speak out of turn.

The gun operates based on the concept of delayed auditory feedback. An attached microphone picks up the sound being made by the target and plays it back 0.2 seconds later. The effect is incredibly confusing to the human brain, making it all but impossible to talk or hold a conversation. The device doesn't cause the person it's being used on any physical harm — it simply messes with their head.

When the human brain hears its own speech perfectly in sync during normal speech, it easily processes the input and allows you to largely ignore the sound of your own voice. However, by offsetting the response just a bit, the brain hears your mouth speaking as well as the strange echo effect produced by the gun. This unusual combination is confusing enough to effectively shut down the part of your brain responsible for managing speech, and you fall immediately silent.