Police will force teenage loiterers out of a shopping area by bombarding their eardrums with a piercing noise only young people can hear.

Dubbed the "chavbuster" but officially called a Mosquito, the electronic gadget acts like a dog whistle, emitting a high-frequency noise only audible to teenagers, who do not suffer progressive hearing loss until age 20 onwards.

It will now be used in Crawley to disperse teens who hang around the Pound Hill parade of shops.

Residents and shopkeepers complain they attempt to buy alcohol and cigarettes and sometimes commit more serious antisocial behaviour because there is not enough for youngsters in the area to do.

Karen Waddingham, shop supervisor at the Coop in Pound Hill parade, welcomed the move.

She said: "We do have a lot of kids hanging around asking people to get them cigarettes and alcohol, so I think it's a good idea.

"Some of the older people don't like coming out in the evening because of the youngsters and it would be ideal during the summer holidays."

Alex Dillon, manager of The Master Fryer fish and chip shop, said he was sick of the antisocial problems in the area but was concerned the device could disturb innocent shoppers and workers.

Mr Dillon said: "We've had little kids coming round the back of the shop scratching my car up with keys, so if it stops that then I'm all for it.

"But we are a chip shop so we have people between the ages of 16 and 18 working here, and if it stops people coming down in the summer holidays, I wouldn't want it.

"You can't tell until it goes up, but once it's up, it won't be coming down will it?"

The Mosquito is a speaker housed in a black box which can be used over a range of 20 metres and is billed by manufacturer Compound Security as an "ultrasonic teenage deterrent".

It relies on the medical phenomenon known as presbycusis or age-related hearing loss which begins at the age of 20.

Inspector Mark Piper said: "We will only use this where appropriate to battle against antisocial behaviour. We've certainly had more than enough reports of those sort of problems to justify putting a Mosquito in there."

The police bought the gadget one month ago but are looking for a shopkeeper to operate it.

A privately-owned device has reportedly been used before at Spar of Tilgate in Tilgate Parade but this is the first police-bought gadget in the town. Police are also looking at the possibility of putting up another one in Furnace Green.

It is the second town in Sussex to use the Mosquito.

The Argus reported last month that police in Lancing had installed a device as part of their Operation Save The Streets.

The Mosquito, which costs £600, was invented y Howard Stapleton, of Compound Security systems in Merthyr, who dreamt up the idea after he was irritated by factory noise as a child. It as first used in Barry, South Wales.

It emits tones around 16Khz. Mr Stapleton has spoken to Defra (the Department for Environment, Food and Rural Affairs) and his local environmental health department and says it is harmless, even with long-term use.

A spokeswoman for Spar said: "Mosquito alarms are being trialled in selected Spar stores.

"Occasionally, some stores have issues with young people congregating outside, which can be intimidating for some customers and staff."