Philadelphia Parks Are Using Sonic Devices to Keep Teenagers from Hanging Around at Night

In a move that seems as if it belongs in a dystopian novel about persecuted teenagers, the city of Philadelphia has started using sonic noise devices as part of an anti-vandalism strategy to keep would-be destructive young people away from their parks and other public places after dark.


The noisemakers emit a constant, high-pitched noise from 10 p.m. until 6 a.m. – a noise of a such a high frequency that only teenagers and young adults can hear it. People between the ages of 13 and 25 have especially acute hearing when it comes to range; after that, cells in our ears begin to die off, which leads to trouble hearing higher-frequency noises.

In a perhaps predictable turn, people in the area are concerned that the devices could be giving them headaches or even damaging their hearing, according to people interviewed. One of them, a 27-year-old named Mary Kate Riecks, avoids the block near her house because one of the machines was recently installed.


“It almost is more like a feeling than a sound. It, like, kind of is in the back of your head. And it – at least for me, I get a headache if I’m near it for too long, so I usually skip around this block or, like, walk very quickly down it.”

The device, called a Mosquito, is an “acoustic deterrent device” designed to keep humans and/or animals away from certain areas. They’re typically used by law enforcement or the military, so Philadelphia’s use of it in public spaces is certainly controversial.

The Mosquito is manufactured by Moving Sound Technologies, a Vancouver-based company, and president Michael Gibson says he’s distributed Mosquitos to 20 or so parks departments in US cities.


“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.”

Not everyone in Philadelphia finds them to be non-confrontational – or acceptable. Councilwoman Helen Gym refers to them as “sonic weapons.” She, and others, told NPR they’d like to see them gone for good.

“In a city that is trying to address gun violence and safe spaces for young people, how dare we come up with ideas that are funding by taxpayer dollars that turn young people away from the very places that were created for them.”


Not only are some concerned about the social ramifications, but they also argue that we don’t know if there might be long term effects on people’s hearings or on the local wildlife.

There are currently 30 devices in the city, each of which cost around $5,000. Mosquitos have been banned in other municipalities all over the world, including Washington D.C., but for now, park officials in Philadelphia are still defending the device as part of what they call a comprehensive anti-vandalism policy.

At 33 seconds into this NPR radio story, there is a tone that supposedly only young people can hear. Can you hear it? Didn’t hear anything? If so, it’s likely you are not between the ages of 13 and 25. That’s the age group this sound is targeted toward.

More complaints could lead to the city council considering the issue more seriously, but there’s no law against Mosquitos – so if you’re out at night and come home with a headache…well, it could be that the night air is not so refreshing as it should be.

Or maybe just not as quiet.