This weapon is designed to inject blasts of sound directly into a person's head from a couple of hundred yards away.
Microwaves enter the head directly through the skull, not the ear, so protective earplugs are useless. The inner ear will sense the microwave and recognize it as sound. And the microwave blast can be adjusted to create different kinds of sounds.
Versions being developed include bulk microwave-emitting systems for the Army and small, rifle-style versions for the Marines and special operations forces. Some early versions have been field-tested in Iraq and Afghanistan.
It's also envisioned that police could use versions of the gun for crowd control -- "sound bullets" instead of nonlethal rubber pellets. Sierra Nevada Corp., headquartered in Sparks, Nev., is working on a version of the microwave ray gun under a U.S. Navy research.