A speech Jamming Gun? Oh THIS is what we need.

[Justice wanted]

http://www.rawstory.com/rs/2012/03/03/watch-video-of-the-japanese-speech-jammer-gun-in-action/

Basically you point the jammer at the person speaking. When it is activated it make the speak hear their voice repeated back to the speaker basically confusing them.

IF this thing is for real I can see Police departments using this on protesters.

[Devil_Fish]

1. They do.

and the speaker heres the voice in their head. no one else can here it.

[saras]

4. That's a different gun. You can make those at home too.

That's the one with two ultrasonic transducers, and the beat frequency between them (the voice you hear) is only created by the nonlinearity of your ears and auditory nerves. With THAT gun, you don't need to mic them and feed it back, it's easier to just blast them with intolerable noise (since no one else hears it).

THIS device, for better or worse, only stops coherent, rational speech. It will NOT stop you from chanting slogans, or yelling and screaming, and for that matter, if you've been in a punk band for a few years you can probably just ignore it like you ignore a bad PA, as long as you've got your schtick memorized.

A weapon that attacks rational speech but not slogans - doesn't THAT sound like a right-wing dream!

I call the other one a "schizophrenia gun" - a couple of 100 watt piezo tweeters from a PA, a stereo amp that works up to 200KHz or so, a laptop and a mic, and you're good to go.

[Historic NY]

2. Is there an echo in here?....

happens now if you have even encountered a pesky audio system.

[Kurmudgeon]

3. I expect bad reactions to this technology.

While the user may be at a distance, they are effectively putting their hand over someone's mouth.
It may stop people from speaking, but it won't stop them from doing other things.
It's only real use is escalation. I could be wrong and I hope I am, but we'll see.