It is feared the sounds emitted are loud enough to damage eardrums and even cause fatal aneurysms.

The technology has attracted safety concerns possibly because the beam is often confused with the microwaves commonly used by consumers to rapidly heat food.

“There are a lot of misperceptions out there,” lamented Taffola, saying the Pentagon was keen to make clear what the weapon is, and what it is not.

The frequency of the blast makes all the difference for actual injury as opposed to extreme discomfort, stressed Stephanie Miller, who measured the system's radio frequency bioeffects at the Air Force Research Laboratory.

The system ray is 95 gigahertz, a frequency “absorbed very superficially,” said Miller.

"The beam only goes 1/64th of an inch (0.4 millimeter), which “gives a lot more safety.

“We have done over 11,000 exposures on people. In that time we've only had two injuries that required medical attention and in both cases injuries were fully recovered without complications.”

In contrast, microwave frequency is around one gigahertz, which moves faster and penetrates deeper - which is how it can cook meat in an oven, said top researcher Diana Loree.

With the transmitter, a wave 100 times the power of a regular microwave oven cannot pop a bag of popcorn “because the radio frequency is not penetrating enough to heat enough to internally heat the material,” she stressed.

Read more: http://www.smh.com.au/technology/technology-news/us-military-turns-up-the-heat-on-rioting-mobs-20120312-1utbj.html#ixzz1otUIcGfV

Britain's military will be armed with a sonic device that can be used as a high-volume loudspeaker or a non-lethal weapon to disperse crowds at this year's Olympic Games in London, the defence ministry said.

The equipment, which can project a piercing sound over hundreds of metres causing physical pain, has been used during protests at the G20 summit in Pittsburgh in 2009 and against pirates operating off the Somali coast.

The Ministry of Defence said it expected to use it primarily in loudspeaker mode to communicate with boats it wants to stop on the River Thames.

Defence chiefs have already caused controversy by announcing plans to put surface-to-air missiles on the top of residential buildings near the Olympics site in east London.

http://www.abc.net.au/news/2012-05-12/britain-to-deploy-sonic-device-at-games/4007566

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