Karen Piper, Carnegie Mellon Prof, Sues Pittsburgh Over G20 Hearing Loss

09/21/2011 01:23 pm ET | Updated Nov 21, 2011

PITTSBURGH — A university professor says in a federal lawsuit against the Pittsburgh police that her hearing was damaged when officers used a giant speaker to disperse protesters during the Group of 20 economic summit two years ago.

The American Civil Liberties Union is representing Karen Piper, then a visiting professor at Carnegie Mellon University. The lawsuit says Piper was a bystander when protests occurred near the university on Sept. 24, 2009.

That's when officers used the Long Range Acoustic Device. The suit says the device "emits harmful, pain-inducing sounds over long distances."

Piper says it damaged her hearing. Police have called it an effective crowd-control device.

City police referred a call for comment to the city Law Department, which didn't immediately return a message.