Clive Robinson • March 22, 2018 3:34 PM
First of cross modulation is not exactly an unknown problem, nor for that matter making highly directional beams with way way less directional radiators (look up how the German bombing beams worked ProfR.V.Jones detailrd it in his 1973 book “Most Secret War”).
The thing to remember is concussion that effects the human brain is generally a very low frequency effect not up in the KHz band. Also it requires a considerable amount of energy in impulse form.
Thus I’m doubtfull that what was recorded on the mobile phone was the direct output of a sonic weapon. Further their discription suggests that there was atleast a third frequency involved to make the chirping effect (the output of a “two tone test” is a third tone, not one that is envelope modulated).
Back in the 1960’s and later in the 1980’s there was research carried out in the UK into crowd control beam weapons. The problem in the 60’s were inefficient radiators, this improved considerably in the 80’s and there were viable weapons developed. One using lower ultrasound frequencies generated an intermodulation product in human skin designed to specifically mimic the waveforms and frequencies the human nervous system was most sensitive to. During tests they produced unconciousness and even death in human analogue (porcine) test subjects at over 500M (~2000ft). They found that they could also pick out just one test subject of several closely associating. But the human body does respond to some higher frequencies just on the edge of the low frequency hearing range upto a couple of hundred Hertz. We know this from various “industrial diseases” such as “Miners White Finger”.
There is a more modern version of such anti-personnel sound devices the “Mosquito” being one that actually uses frequences that only teenagers and younger can hear. Another is the so called “cone of secrecy” where audio messages can be selectively delivered to individuals in a gathering. Then of course there are the sound weapons you will now find mounted on ships that have to sail in waters such as around Somalia where piracy has become common practice again.
Whilst such devices have been built and tested and actively deployed their ultrasound brethren hardly made it out of the experimental labs.
As others have noted above and where this subject has come up before, there are distinct problems with all but the lowest of ultrasound frequencies in that they do not propagate very well in air especially when variable humidity and air pressure are involved.
As I’ve noted on this blog before all propergating mediums tend to have charecteristics that are frequency dependent. Thus they will be effectively transmissive / reflective / absorbing at various points in the spectra. This applies to all forms of energy that can be radiated or conducted.
What has happened since the begining of this century is the improvments in semiconductor devices and similar in the top end of the microwave / bottom end of the Infrared EM spectrum. As some will be aware these are not realy “natural frequencies” thus we realy don’t know much about the effects they have on the human body in part or whole (other than simple heating models).
What we do know is that non reactive components absorbe energy and via various processes convert it to the ultimate form of polution which is “heat”. We also know that dielectric heating can cause problems (eggs in microwaves). Where some organics are transmissive whilst other are absorbers at the same frequency thus “Cooking from the inside out” is possible.
Then there are the issues of resonance. As Tesler discovered in the first part of the last century, tuned devices when arranged correctly can masively multiply the voltage, which in turn very much raises the heatibg effect (W=V^2/R).
But other effects can happen, a short pulse of energy can be integrated by both a tuned circuit and an absorber. Thus a train of such pulses will in effect be demodulated and cause localised non EM effects such as sound waves and high energy physical movment as well as heating
If there has been any research into the characteristics of the human skull and white/grey matter of the brain over and above the heating effects of EM radiation I’m not actually aware of it.
That said there has been widspread reports of various illnesses and coresponding diseases due to high levels of near and low freaquency RF microwave frequencies. Especially in children and adults having higher than average cancers appraring around transmitter masts etc. Whilst objective science appears a bit thin on the ground, you have to remember that it would not be ethical to experiment on humans.
Which does not rule out the possibility that some people have been extreamly unethical but in secret (The Russian’s and their CWC avoiding nerve agent development being a prime example in the news currently).