Mechanisms of auditory hallucination are currently a mystery to medical understanding. Though hallucination is defined as a perception without a stimulus, there are technologies capable of remotely simulating hallucination.  One of these technologies is based on the fact that radio frequencies produce sound within absorbing materials when pulsed to sufficient peak power.  This phenomenon is usually termed microwave hearing, and is validated in review.       There are considerable authentic references to the development of voice transmission based on the microwave hearing effect, which is also known as radio frequency hearing. Remote microwave voice transmission technology has long been discovered,  developed,    detailed in patents,     and designated as a weapon   with deleterious applications discussed.    Duplicated effort is usual to classified development, and successful demonstration of this voice transmission technology is indicated twice: first by magazine news report of manufactured device demonstration,  and stated by a later developer,  yet details remain classified.  That such technology can be applied remotely with coupling to target tracking technology and through wall radar capability 1 has implications for diagnosis, because complaint of ‘hearing voices’ features in a number of mental disorders.
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