* Injuries alleged at protest over Eric Garner death
* Judge says 'reasonably plausible' NYPD acted unnecessarily
* New York City calls sound cannons safe, evaluates steps
By Jonathan Stempel
NEW YORK, June 1 (Reuters) - The New York City Police Department failed to persuade a federal judge to dismiss a lawsuit claiming it used excessive force by employing military-grade sound cannons, which can emit ear-piercing noise, to disperse protesters.
In a decision on Wednesday, U.S. District Judge Robert Sweet in Manhattan said people who claimed to suffer hearing loss, migraines, ringing in the ears and other injuries at a Dec. 5, 2014, protest over the death of an unarmed black man at the hands of police could seek damages.
The plaintiffs - including photojournalists, activists, a photographer and a graduate student - were protesting a grand jury decision not to indict a white policeman whose chokehold led to the death of Eric Garner in July 2014.
Armed with videos of the protest, they objected to the NYPD's use from 10 feet away of a Long Range Acoustic Device (LRAD), which can be used to disperse crowds through volumes that can top 120 decibels, louder than sandblasters and power saws.
"The protest involved large numbers of people and so it is understandable that the officers would want to increase the volume of their message to reach the largest number," Sweet wrote.
"However, the allegations and video make the protest appear broadly in control, even when glass bottles were thrown from the crowd toward the police," making it "reasonably plausible" that the LRAD was unnecessary, he said.
Sweet also said the plaintiffs could pursue claims over the alleged improper training of officers, and for assault and battery.
He rejected claims over alleged free speech violations and illegal seizures, and dismissed all claims against former NYPD Commissioner William Bratton.
"The Long Range Acoustic Device is an effective and safe communication tool," Nick Paolucci, a spokesman for the city's law department, said in a statement. "We are reviewing the decision and evaluating our next steps."
Gideon Oliver, a lawyer for the plaintiffs, said in a statement he hopes the NYPD will change its policies to reflect how LRADs are "potentially deadly crowd control tools, requiring training and supervision to use safely."
According to the plaintiffs, the NYPD began employing LRADs during the 2004 Republican National Convention, but waited a decade before using them regularly at protests.
LRADs are made by San Diego-based LRAD Corp, which is not a defendant in the lawsuit.
The case is Edrei et al v. City of New York et al, U.S. District Court, Southern District of New York, No. 16-01652. (Reporting by Jonathan Stempel in New York; Editing by Bill Trott)