A powerful speaker that’s capable of causing hearing damage and is used by a growing number of police around the world isn’t merely a “communication device” but, potentially, an instrument of excessive force, a federal court ruled on Wednesday.

The U.S. Court of Appeals for the 2nd Circuit rejected the appeals of two New York Police Department officers who had sought qualified immunity in a federal lawsuit that accuses them of using unconstitutionally excessive force when they deployed a Long Range Acoustic Device made by the LRAD Corporation at a Black Lives Matter protest in 2014.

“The NYPD should overhaul its policies and practices regarding LRAD uses to reflect the reality that LRAD’s are potentially deadly tools, requiring meaningful training and supervision to use safely,” Gideon Oliver, who represents the plaintiffs, said in a statement. The New York City law department did not immediately respond to a request for comment.

The decision affirms a finding last year by U.S. District Judge Robert Sweet of the Southern District of New York, who ruled that LRADs are akin to so-called “distraction devices,” like flash-bang and concussion grenades,” which are potentially harmful. Lawyers for the plaintiffs called Wednesday’s decision “precedential.”

The concerns over LRADs echo those surrounding a range of military-grade gear that is increasingly being used by police across the country, both Pentagon hand-me-downs like armored trucks as well as high-tech surveillance devices like Stingrays. While some local efforts are afoot to bring more transparency and public oversight to new…