The gun works by listening in with a directional microphone, and then, after a short delay of around 0.2 seconds, playing it back with a directional speaker. This triggers an effect that psychologists call Delayed Auditory Feedback (DAF), which has long been known to interrupt your speech (you might’ve experienced the same effect if you’ve ever heard your own voice echoing through Skype or another voice comms program). According to the researchers, DAF doesn’t cause physical discomfort, but the fact that you’re unable to talk is obviously quite stressful.
Suffice it to say, if you’re a firm believer in free speech, you should now be experiencing a deafening cacophony of alarm bells. Let me illustrate a few examples of how this speech-jamming gun could be used."