Repellent sound gets youths to just buzz off

Switch on the small, gray metal box and listen: A sharp, pulsating, high-pitched tone burrows into the ear like a power drill bit, prompting an agitated, please-shut-that-blasted-thing-off grimace. That’s what you hear if you’re between the ages of 13 and 25.

If you’re not, you may not sense a thing.

Howard Stapleton himself can’t hear the sound he conjured up three years ago. His daughter, Isobel, then 15, had come home in tears from a store in their town in south Wales, after having been harassed by other teens.

The store owner told Stapleton that he and other merchants and customers wanted the young toughs gone too but feared to confront them.

As the 41-year-old security device inventor contemplated the problem, he recalled from his teen years the awful buzz of an ultrasound welding machine at his father’s factory. He remembered that his complaints about the noise were met with quizzical looks from workers: “What noise?”

From that impulse to help rid his local market of loiterers came his invention, “the Mosquito,” an electronic contraption that emits a high-pitched pulsating sound that can mostly be heard only by teens and people in their early to mid-20s. An age-related hearing loss called presbycusis reduces the ability to hear high-pitched sounds after the late 20s. The device is mostly inaudible to older adults, young children and pets.

In the United Kingdom, the Mosquito has become the next big thing in crowd and crime control -- and it may one day be coming to a teen hangout near you. The device seems to have ratcheted up the aural warfare that began a few years ago when train stations and merchants in England tried piping in classical music to repel young loiterers. It entered the U.S. market last fall.

The Mosquito emits a sound that can be heard up to 60 feet away for 20 minutes at a time. It can be heard through earphones and over loud music. It is for commercial and official use only and is never supposed to be used in a residential area or near a bus stop, the manufacturer says.

Young people, meanwhile, have turned the tables on the technology. Many have downloaded the sound onto their cellphones, creating a ring tone that they can hear but older adults can’t. Teen Buzz, a short Mosquito ring tone, is among the most downloaded ring tones worldwide. Some use it to alert high school classmates of recently sent text messages. For others, it has come in handy when parents curtail use of their cellphones.

“I was watching an episode of ‘Law and Order’ the other day where they called the ring tone ‘the Bumblebee,’ ” said Jerry Whiting, a Seattle Web designer who created the ring tone for free downloads on his ad-based site, jetcityorange.com. Since the ring tone was posted 18 months ago, Whiting said, the site has received 1,000 hits a month.

“I thought it was a passing fad, but with the saturation of cellphones, it turns out that I clearly underestimated the popularity,” he said.

The Mosquito’s price typically ranges from $1,250 to $1,895.

Already, the device has helped with youth crowd control at a school system in Columbia, S.C. Rick McGee, emergency services manager at Richland School District Two, said that the schools purchased two Mosquitoes two months ago, installing one in a vehicle and mounting the other in a commons area.

“What we like about them is that you can move crowds without getting into a confrontation,” McGee said. “We use the car device at sporting events, in the parking lot after the games where people start congregating and the problems start. We’ll switch it on and immediately you’ll see heads turn around. They become irritated from the noise, and within about five minutes, they’ve all gone somewhere else.”

At his home in Merthyr Tydfil in Wales, inventor Stapleton tried re-creating the sound from his youth. He tested various attempts on his children, until they responded to a 17-kHz tone at 85 decibels (db). He then ramped up the irritating sound by making it peal at four times a second. Stapleton ultimately manufactured the Mosquito for commercial and law enforcement use worldwide through his company, Compound Security Systems.

Since then, he has sold more than 4,000 of them and earned the equivalent of $500,000. He’s dismayed by people who have converted the sound into a ring tone without his permission. Even worse are those who set up “kid-free zones” by running the Mosquito 24 hours a day.

Stapleton says that at 85 db, the sound is equivalent to heavy traffic and would do permanent ear damage if someone were exposed to it for eight continuous hours. The level is also the U.S. federal noise standard to which workers can be exposed without wearing protective gear.

“One-time exposure to 85 db . . . will not necessarily cause hearing loss,” said Colleen E. Ryan-Bane, an audiologist at Johns Hopkins University. “However, prolonged, consistent exposure to 85 db and above will cause hearing loss.”

U.K.-based human-rights groups have complained that the device discriminates against young people.