![The Mosquito Alarm is designed to repel youth away from areas by playing noise at a frequency most adults can't hear. : r/HostileArchitecture The Mosquito Alarm is designed to repel youth away from areas by playing noise at a frequency most adults can't hear. : r/HostileArchitecture](https://i.redd.it/qchepuk2agt51.jpg)
The Mosquito Alarm is designed to repel youth away from areas by playing noise at a frequency most adults can't hear. : r/HostileArchitecture
![How good is your hearing? See if you can hear high pitch noise used to deter anti-social youngsters - Daily Record How good is your hearing? See if you can hear high pitch noise used to deter anti-social youngsters - Daily Record](https://i2-prod.dailyrecord.co.uk/incoming/article10859778.ece/ALTERNATES/s615b/mosquito-mk4-large.jpg)
How good is your hearing? See if you can hear high pitch noise used to deter anti-social youngsters - Daily Record
![Couple who installed high-pitch 'mosquito' alarm to ward off racist teen vandals are now under investigation for noise nuisance | Daily Mail Online Couple who installed high-pitch 'mosquito' alarm to ward off racist teen vandals are now under investigation for noise nuisance | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2013/06/18/article-2343706-1A608FDA000005DC-65_1024x615_large.jpg)
Couple who installed high-pitch 'mosquito' alarm to ward off racist teen vandals are now under investigation for noise nuisance | Daily Mail Online
![Sonic devices installed at 30 Philadelphia parks to prevent young people from loitering - 6abc Philadelphia Sonic devices installed at 30 Philadelphia parks to prevent young people from loitering - 6abc Philadelphia](https://cdn.abcotvs.com/dip/images/5353639_061919-wpvi-curfew-park-buzz-4pm-vid.jpg?w=1600)
Sonic devices installed at 30 Philadelphia parks to prevent young people from loitering - 6abc Philadelphia
![Couple who installed high-pitch 'mosquito' alarm to ward off racist teen vandals are now under investigation for noise nuisance | Daily Mail Online Couple who installed high-pitch 'mosquito' alarm to ward off racist teen vandals are now under investigation for noise nuisance | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2013/06/18/article-2343706-1A60A0E7000005DC-11_296x297.jpg)