In Philadelphia, the city has installed sonic devices within parks to target teenagers and “keep unwanted people out of parks,” as reported by NPR’s Morning Edition. The “Mosquitos” are acoustic deterrent devices that transmit a sound targeted at people between the ages of 13 and 25. If you’re ready for a minor headache, go ahead and give NPR’s broadcast a listen to hear a sample of it. 

The devices are programmed to constantly emit the high-frequency noise from 10 p.m. to 6 a.m. every single night. Last month, a report from WPVI found that Philadelphia has about 31 Mosquito devices in the city’s parks. Almost every single facility listed was a playground or recreation center. The devices — produced by Vancouver-based Moving Sound Technologies MST) — costs about $5,000 each to buy and install. 

Although some city officials justify their decision to use these devices by saying they’re meant to discourage vandalism, that excuse doesn’t fly with everybody. Philadelphia Councilwoman Helen Gym described the devices as sonic weapons to the Morning Edition, adding:

“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 funded by taxpayer dollars that turn young people away from the very places that were created for them? … I don’t think that this project is going to go any further until it meets with the full scrutiny of the public and that we have some serious attention paid to whether this is the best use of our money.”

Acoustic deterrent devices have been used in other cities before, including Washington, D.C. Back in 2010, the city’s use of the devices was challenged after — then 28-year-old — Dave Moss heard the sound while passing through the city’s Gallery Place Metro station. According to NBC, Moss and members of the National Youth Rights Association, filed a complaint with the D.C. Office of Human Rights. They alleged that the devices constituted as age discrimination. 

“I think that in many ways society is going in reverse on how we deal with our young people,” Moss told NBC. “It used to be ‘seen and not heard,’ then it was not seen and not heard, and now it seems to be not seen, not heard and must endure sonic warfare if they try to go outside.”

Unfortunately, hostile architecture within cities is nothing new, and it often goes unnoticed by those it doesn’t target. For example, many cities have put up spikes made of concrete or metal or slanted benches to discourage homeless people from sleeping there.

While the Mosquito devices may not technically be hostile architecture — as they’re installed speakers and not necessarily incorporated into the design of a space — they are an example of cities going after vulnerable communities rather than extending resources to them. 

Mosquito devices are yet another way that cities criminalize youth. These devices make youth feel unwelcome and uncomfortable in their own city.