PUPILS PERFORM ‘ALARMING’ FEAT (Mosquito Alarm)

"A high-pitched alarm which cannot be heard by adults has been hijacked by schoolchildren to create ringtones so they can get away with using phones in class. Techno-savvy pupils have adapted the Mosquito alarm, used to drive teenage gangs away from shopping centres. They can receive calls and texts during lessons without teachers having the faintest idea what is going on.

The alarm, which has been praised by police, is highly effective because its ultra-high sound can be heard only by youths but not by most people over 20. School children have recorded the sound, which they named Teen Buzz, and spread it from phone to phone via text messages and Bluetooth technology.

The Mosquito technology is said to play on a medical phenomenon called presbycusis, or age-related hearing loss. It is thought to begin at 20 and first affect the highest frequencies - 18 to 20kHz. " -compsec

Photo: "Teen repellent: inventor Howard Stapleton with the "small and annoying" Mosquito device. The New York Times

Original story:

So far, the Mosquito has been road-tested in only one place, at the entrance to a convenience store in the town of Barry, South Wales. Surly teenagers used to plant themselves just outside the door, smoking, drinking, swearing at customers and making disruptive forays inside.

Robert Gough, who owns the store with his parents, said the youths would sometimes fight, steal and assault staff. Last month, Mr Stapleton gave him a Mosquito for a free trial. The results were almost instant. It was as if someone had used anti-teenager spray around the entrance. Where youths used to congregate, now there is no one."