About 1 a.m. on Dec. 5, 2014, the police used a model called the 100X to emit a series of sharp, piercing beeps directed at people who in some cases were less than 10 feet away. Soon afterward, six of those who were nearby at the time and said they had developed migraines, sinus pain, dizziness, facial pressure and ringing in their ears filed a lawsuit challenging the police’s use of the device.

On Wednesday, a federal judge ruled that the sound it emitted could be considered a form of force.

The use of the device “as a projector of powerfully amplified sound is no different than other tools in law enforcement’s arsenal that have the potential to be used either safely or harmfully, one example being distraction devices — items like stun grenade, flash bang, or concussion grenades,” Judge Robert Sweet of Federal District Court in Manhattan wrote, adding, “It can be plausibly inferred that the use of a high-powered sound magnifier in ‘close proximity’ to plaintiffs was not appropriate.”

Judge Sweet dismissed the plaintiffs’ claims against William J. Bratton, who was the police commissioner at the time of the episode, and agreed with the argument by lawyers for New York City that the use of the device did not violate First and Fourth Amendment rights.