The sound annoys teenagers so intensely that they have to clutch their ears. Eventually, once they can stand it no longer they have to move on.
Adults however, are completely immune because of the body's natural ability to detect some frequency wave bands diminishes almost entirely after 20.
Police are backing the Sonic Teenager Deterrent, nicknamed the Mosquito because of its sound.
The gadget is a small black box that costs £622. This can be attached to the outside wall of shops, offices and homes, and sends out a series of 80-decibel bursts of pulsing sounds at up to 16khz.
It is said to sound like a demented insect or a very badly-played violin.
Howard Stapleton, a businessman and former electronics apprentice at British Aerospace, who was sick of youths hanging around outside his shop, came up with the idea.
Working in his bedroom in Merthyr Tydfil, and using his four children as guinea pigs, he came up with a prototype of his device and asked the local shop to test it.
"I got it so that only my kids hated it and my fianceé and I were completely unperturbed," he said. "We put up the prototype outside the store and almost immediately people stopped congregating.
"The beauty of it is that the noise does not have to be loud, just pitched at the right level which affects teenagers."
- Phil Simms