June 27, 2006 — If classical music or light jazz isn't enough to deter loitering teens, shopkeepers might consider installing a Mosquito over the entrance to their store or restaurant.
It's not a bug but a box that emits a harmless, high-frequency sound that can only be heard by people under the age of 20.
Invented by security consultant Howard Stapleton, founder of Compound Security in Merthyr Tydfil, South Wales, the Mosquito could be the next best thing to Barry Manilow for driving away young dawdlers who pose a threat to property or paying customers.
"It's horrid. The frequency is right at the top end of hearing for teens. That's what makes it highly annoying," said Stapleton.
Stapleton conceived of the idea last summer after talking with a store owner who was having a serious problem with loitering youths. After brainstorming options, including classical music, Stapleton remembered a bothersome sound he had heard as a teenager, while visiting his father at a factory. No one but the young Stapleton could hear the excruciating noise and later he learned why.
It was presbycusis, or age-related hearing loss, which is usually caused when cells inside the ear naturally deteriorate.
"It is true that starting somewhere around 21, things begin to deteriorate at those high pitches and they begin to fade away," said Ellen O'Neil, associate director of audiology at the Massachusetts Eye and Ear Infirmary in Boston.
Although people can hear frequencies between 20 and 20,000 hertz, they only use frequencies between 250 and 8,000 hertz to communicate. As a result, they don't notice when the higher frequencies start to fade.
But when a high-pitched noise is heard over a few minutes or more, it becomes maddening. And Stapleton's Mosquito capitalizes on kids' capacity for hearing well.
Meant to hang over a doorway and be switched on as necessary, the device emits pulses of barely audible frequencies ranging highest audible frequencies of 18,000 to 20,000 hertz.
According to Stapleton, it takes several minutes before a young loiterer might notice the noise and 10 to 15 minutes before it becomes annoying. In this way, the Mosquito does not deter young customers; it just encourages them to move along.
Since the first sales of the Mosquito launched back in January, Stapleton has sold 1,000 devices mostly in the United Kingdom. The company recently launched a smaller version that adjusts its volume according to surrounding street noise and beep in the audio range to make everyone aware of its presence.
Stapleton is also marketing a ring tone, called Mozzy Tone, which is based on the Mosquito. Teens can download it to their mobile phone to receive calls or text messages without adult being any the wiser.
