You've got a cell phone jammer to jam those annoying people who talk loudly on their cell phones, but what about real life yakkers?
Enter Japan and this diabolical - or genius, your pick - invention of the SpeechJammer:
The design of the device 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.