City officials in Philadelphia are under attack for their increasing use of an acoustic deterrent—described by a local councilwoman as a “sonic weapon”—to keep the city’s children and young adults away from certain recreational areas at night.
The Mosquito, invented in the U.K. back in 2005, is described by the product’s Canada-based North American distributor as a “small speaker that produces a high-frequency sound much like the buzzing of the insect—this high frequency can be heard by young people 13 to 25 years old,” and reaches as far as 130 feet, depending on the set volume.
Hearing deteriorates with age, and so older people cannot hear the high (17.5 to 18.5 kilohertz) frequencies emitted by the $5,000 devices, which Philadelphia has been deploying since 2014 and is now in 31 locations to “prevent loitering and vandalism.”
Micahel Gibson, the CEO of distributor Moving Sound Technologies, told NPR that “the intention was just to move, non-confrontationally, youth from an area where they should not be. And that will prevent vandalism. It’ll prevent graffiti, loitering.”
City officials have deemed the technology to be safe, but it has raised safety concerns overseas. A health regulator in Germany reported that although the risk to teenagers is “relatively low,” for smaller children there is a risk from lengthy exposure, with adults unable to hear and move away. “The onset of dizziness, headache, nausea and impairment is to be expected.”