I'm sorry, Terrat, I don't quite see the connection here. I read the articles that you cited and here's what I found.
In 2003, Richard E. Lord was part of a controlled experiment that tested infra-sonic frequencies piped through a 23ft long tube on volunteers to ascertain the effect it had.
In a separate article, on a different website, it was revealed that the government is working on Ultrasonic frequencies to disable people.
In your third link, there's an ominous looking picture of a flat panel Sound Cannon.
After reading all of these articles, I fail to see how you could assert that REL makes weaponry, based on the evidence you provided.
1) The article on Mr. Lord states the British experiment was researching the effect of infrasonic frequencies (Ultra-low frequencies) on the human body. According to the other article you provided, the weaponry used by the military is all in the Gigahertz range or laser-based, i.e. high frequencies.
2) The reactions observed in the British Experiment were "anxiety, extreme sorrow and chills." The effects of the military's experiments, cited in the 2nd article and those linked to it were that the devices were used to induce confusion, pain and temporary paralysis.
3) The Sound Cannon appears to be flat, fairly thin and about 4 feet wide. The infrasonic waves that Mr. Lord was generating required a 7m long pipe to generate. Although ultra-low frequencies demand high power, high excursion and enormous surface area to generate, high frequencies can be generated with almost negligible motion and little power.
As a side note, this is why many Electrostatic panels and Planar Magnetic speakers are accused of not generating enough bass energy. Most simply don't have enough radiating surface area to move the air required to generate the lowest frequencies. The ones that do, like the enormous Soundlabs et al. are so big they take up an entire room.
4) Although it's possible that a device might generate infrasonic waves without having to move a ton of air, I bet every audiophile on the planet would be excited to find a subwoofer that was only a few inches thick that could generate infrasonic frequencies!
I think Terrat, you may be barking up the wrong tree here. Not only are the frequencies in each article at polar opposites of the sonic spectrum, but the reactions observed and their uses are vastly different. Although I can appreciate that making a crowd of volunteers really sad might appear sinister to some, I'm not sure any military power on the planet would be much interested in merely depressing their target. I would think any military worth their salt would be much more interested in using microwaves to instantly heat up the water stored 1/64th of an inch under the skin, instantly crippling the target or using ultrasonic waves to disrupt the sensory system or create intense pain without tissue damage. Both of these results are cited or linked from the 2nd article.
