Watch: US Military Laser Weapon Makes Voices From Thin Air

The U.S. military is developing a non-lethal weapon that could one day use laser technology to create noise miles away from the device itself. Years in the making, scientists can use the technology to create sounds almost like a human voice from thin air.

Skip to about 18 seconds in the video above, provided by the U.S. military's Non-Lethal Weapons Program. Behind the high-pitched whine, you can hear a sound similar to human voices coming through a walkie-talkie. As well as noise, the device can produce light and even heat.

Still in the development stages, the military hopes to have a "Laser-Induced Plasma Effect" weapon within about three years, Defense One reports.

An ultrafast pulse laser shoots focused light for around ten seconds, Defense One states. This strips air molecules of their electrons, creating a small cloud of plasma. A second, finely tuned laser manipulates the plasma field, generating both light and sound. The right kind of manipulation can produce sounds similar to ghostly radio voices.

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"We're this close to getting it to speak to us. I need three or four more kilohertz," David Law, who runs the U.S military's Joint Non-Lethal Weapons Program technology division, told Defense One.

The weapon produces noise at a specific point in space, depending on where it is pointed. That means you could potentially create the sounds at a great distance from the weapon itself, depending on the size of mirrors used to manipulate light.

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"Range is a function of the optics. The bigger the mirrors, the [farther] the range," Law explained. A five-inch mirror translates into an effect about 0.6 miles away. An eight-inch mirror, he added, could create the effect some three miles away.

Plasmas, Law said, have been created at a range of up to 19 miles. "This is the first non-lethal weapon that could go out tens of kilometers," he said.