A high-pitched "dog whistle" device is to be used by police in north Staffordshire to stop groups of nuisance youths hanging around shops.
The Mosquito sends out a pulsing 80-decibel frequency noise which can usually only be heard by teenagers and those in their early 20s.
It is now being piloted at two locations in Leek.
The device, which costs £622, is fitted outside the shop and can be turned on by shopkeepers to move youths on.
Det Insp Amanda Davies, from Staffordshire Police, said: "We identified hotspot areas in the Moorlands where nuisance youths were regularly gathering outside shops and takeaways.
"The traditional methods of dispersal were not working so when we heard about this, we decided to trial it."
The Mosquito is the brainchild of Howard Stapleton, of Compound Security Systems in Merthyr, Wales, who tested a device at a shop in Penydarren, Merthyr.
Research by the company showed the majority of people over the age of 25 had lost the ability to hear at the frequency range used by the Mosquito.
Det Insp Davies stressed the device, which is protected from vandals by a metal cage, did not cause pain and had been vetted for any health and safety implications.
"The noise can normally only be heard by those between 12 and 22 and it makes the listener feel uncomfortable.
"It is not on all the time and it is controlled by the shopkeepers - if they can see through their window that there is a problem, they turn the device on for a few minutes until the group has dispersed," she said.
The trial is in its third week and the police are looking to move the device around the area to a new location every week or two, she added.
She said: "At both the places where it has been piloted the shop owners have reported fabulous results and we've been approached by some who are considering buying their own equipment."