This story originally appeared on PlanPhilly. Markward Playground is a small park near the Schuylkill River. I often go there for a walk or to look at the view, so I was upset to learn that this park ...

Claims of a mysterious "sonic weapon" used in Venezuela fuel speculation about exotic U.S. military technology, though ...

PHILADELPHIA (WPVI) -- Some young people are hearing a high pitched frequency at parks around the city. According to Philadelphia's Parks and Recreation department, a device called "The Mosquito" has ...

DARPA, the governmental department that researches crazy things that may eventually make it into the military, is currently working on an “ultrasonic curtain”. In layman’s terms, it’s a sonic cloaking ...

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. In this country, Philadelphia ...