(NPR) To keep teens away after closing hours, Philadelphia has installed sonic devices in parks. They are noisemakers that mostly the young hear and have been banned elsewhere.
It's called the Mosquito, and it's an acoustic deterrent device, technology used to keep humans or animals away from a designated area. It's usually used by law enforcement or the military. The Mosquito was manufactured by Vancouver-based Moving Sound Technologies. Michael Gibson is the company's president and says he has worked with about 20 parks departments in cities around the country to install his devices.