[NetBehaviour] Pentagon report investigated lasers that put voices in your head.

marc garrett marc.garrett at furtherfield.org
Wed Feb 20 15:48:19 CET 2008

Pentagon report investigated lasers that put voices in your head.

by Lisa Zyga

A recently unclassified report from the Pentagon from 1998 has revealed 
an investigation into using laser beams for a few intriguing potential 
methods of non-lethal torture. Some of the applications the report 
investigated include putting voices in people's heads, using lasers to 
trigger uncontrolled neuron firing, and slowly heating the human body to 
a point of feverish confusion - all from hundreds of meters away.

A US citizen requested access to the document, entitled "Bioeffects of 
Selected Non-Lethal Weapons," under the Freedom of Information Act a 
little over a year ago. There is no evidence that any of the 
technologies mentioned in the 10-year-old report have been developed 
since the time it was written.

The report explained several types of non-lethal laser applications, 
including microwave hearing, disrupted neural control, and microwave 
heating. For the first type, short pulses of RF energy (2450 MHz) can 
generate a pressure wave in solids and liquids. When exposed to pulsed 
RF energy, humans experience the immediate sensation of "microwave 
hearing" - sounds that may include buzzing, ticking, hissing, or 
knocking that originate within the head.

Studies with guinea pigs and cats suggest that the mechanism responsible 
for the phenomenon is thermoelastic expansion. Exposure to the RF pulses 
doesn´t cause any permanent effects, as all effects cease almost 
immediately after exposure ceases. As the report explains, tuning 
microwave hearing could enable communicating with individuals from a 
distance of up to several hundred meters.

"The phenomenon is tunable in that the characteristic sounds and 
intensities of those sounds depend on the characteristics of the RF 
energy as delivered," the report explains. "Because the frequency of the 
sound heard is dependent on the pulse characteristics of the RF energy, 
it seems possible that this technology could be developed to the point 
where words could be transmitted to be heard like the spoken word, 
except that it could only be heard within a person´s head. In one 
experiment, communication of the words from one to ten using ´speech 
modulated´ microwave energy was successfully demonstrated. Microphones 
next to the person experiencing the voice could not pick up these 
sounds. Additional development of this would open up a wide range of 


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