Andrew Liszewski / Gizmodo & David Hambling / The New Scientist – 2011-12-18 00:56:17
http://gizmodo.com/5867984/future-riot-shields-will-suffocate-protestors-with-low-frequency-speakers
Future Riot Shields Will Suffocate Protestors with Low Frequency Speakers
Andrew Liszewski / Gizmodo
(Dec 14, 2011) — It’s not the first crowd control tool to use sound waves, but Raytheon’s patent for a new type of riot shield that produces low frequency sound waves to disrupt the respiratory tract and hinder breathing, sounds a little scary.
Crowd control tools like the LRAD Sound Cannon emit bursts of loud and annoying sounds that can induce headaches and nausea. But Raytheon’s non-lethal pressure shield creates a pulsed pressure wave that resonates the upper respiratory tract of a human, hindering breathing and eventually incapacitating the target.
The patent points out that the sound waves being generated are actually not that powerful, so while protestors might collapse from a lack of oxygen reaching their brains, their eardrums won’t be damaged in the process. Phew!
And like Roman soldiers joining their shields to form a large impenetrable wall, these new riot shields can actually be networked together to form a larger acoustical horn, vastly improving their range, power, and effectiveness.
There’s no word on what the long-term medical implications might be if you find yourself on the wrong side of one of these shields. But I imagine the unpleasant experience is not unlike being force-choked from afar by Darth Vader.
Riot Shields Could Scatter Crowds with ‘Wall of Sound’
David Hambling / The New Scientist
(December 14, 2011) — RIOT shields that project a wall of sound to disperse crowds will reduce violent clashes with police, according to a patent filed by defence firm Raytheon of Waltham, Massachusetts.
The device looks similar to existing riot shields, but it incorporates an acoustic horn that generates a pressure pulse. Police in the US already use acoustic devices for crowd control purposes that emit a loud, unpleasant noise.
The new shield described by Raytheon produces a low-frequency sound which resonates with the respiratory tract, making it hard to breathe. According to the patent, the intensity could be increased from causing discomfort to the point where targets become “temporarily incapacitated”.
Acoustic devices haven’t seen wide adoption because their range is limited to a few tens of metres. The patent gets around this by introducing a “cohort mode” in which many shields are wirelessly networked so their output covers a wide area, like Roman legionaries locking their shields together. One shield acts as a master which controls the others, so that the acoustic beams combine effectively.
Raytheon declined to comment on the work.
“We do not have sufficient technical detail yet to determine if there are any hidden medical implications,” says Steve Wright of Leeds Metropolitan University in the UK. “These are always a concern because of the risk to sensitive bodily functions such as hearing, or even inducing panic attacks in asthmatics.”
The biggest danger, he warns, is that the technology would be used for political control. “If authorities in Egypt or Syria had this, would they use it for dispersal or to shove crowds into potentially lethal harm’s way?”
Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.
