If you’re under 25 and walking down Wheler street by Shoreditch High street station, you might have heard a piercing high pitched noise coming from the entrance of apartment block opposite Bedford house.

The noise is being emitted from something known as a mosquito device, which targets young people as a security measure to keep crime rates low, prevent loitering, vandalism, drug use and drug dealing. It has also been used in the past to deter rough sleepers.

Mosquito devices are set to a frequency of 17.4 kHz – just above the average adult hearing range, making it only audible to persons 25 and under. 

They are primarily used at an even higher frequency, inaudible to humans, to keep rodents and other animals away from certain areas.

However the use of them on humans can have impacts beyond just being uncomfortable to listen to, and past owners of anti-loitering devices – as they are otherwise known, have been urged to take them down.

Children’s commissioner Anne Longfield says: “Mosquito alarms are aggressive and unpleasant devices which specifically target children. ‘Anti-loitering’ tools are cruel and demeaning and should be banned.”

One passerby Ana C, 21 said: “I don’t think it’s fair for devices like that to be used on young people. There are adults who do the same crimes it is supposedly helping to prevent who won’t be effected by it, and there are young people like me who haven’t done anything and are unfairly targeted”

Tower Hamlets council’s Environmental Health Officers deal with noise complaints which can be reported by going to the website, but have no specific guidelines on mosquito devices.

A study undertaken by the German Federal Institute for Occupational Safety and Health says the noise can have further impacts on children and young people, potentially causing pain, migraines, nausea and dizziness.

The minister who commissioned the study concluded that anti-loitering devices should not be used in areas which are likely to have children present, especially since the institute was not able to draw firm conclusions on the risks to health and safety.

Calls to ban the devices from the UK were rejected in 2010 and the decision on whether these devices can be used was given to councils.