"Forget the megaphones. Police will have a much more high-tech — and louder — option to make themselves heard over the din of Manhattan traffic and noisy protesters outside the Republican National Convention," the AP reports. "It's called the Long Range Acoustic Device, developed for the military and capable of blasting warnings, orders or anything else at an ear-splitting 150 decibels."

The department recently bought two of the 45-pound acoustic sound machines for $35,000 apiece, and plans to mount them on Humvees posted outside Madison Square Garden. It would mark the first time the instrument — which can beam sounds for 300 yards or more — has been used by a civilian force.

"We believe we'd be able to use them in a number of scenarios," said Paul Browne, the police department's chief spokesman.

Two possible uses cited by Browne: directing crowds to safety following a terrorist attack or other calamity, and reminding protesters where they're allowed to march and rally.

The military, which has used the machines in Iraq, bills them as a "non-lethal weapon" designed to disperse hostile crowds or ward off potential foreign combatants by delivering prerecorded warnings in several languages and, if needed, an earsplitting screeching noise. But police insist the latter feature won't be used at the convention.

"It's only to communicate in large crowds," Inspector Thomas Graham of the department's crowd control unit said Thursday.

Graham said police had tried out the device in Times Square, and found it delivered clear, even sound over four blocks. Decibel readers will be used to keep the volume at a safe level, he added.