Following up on their advice on how to safely topple a statue using science, Popular Mechanics has another great new article on dealing with LRAD (long-range acoustic device) cannons. A popular choice among riot cops and other militarized police units, LRAD units are capable of violently brutalizing protestors with the excessive force of sound waves — which is better than bullets, I guess, but can still be pretty god damn painful. Audio producer Cory Choy described the experience for Popular Mechanics:
Horrible, nauseating pain hit my body. And then I realized it was sound. At first you just think, ‘What’s happening to me?’ Your body goes into complete pain and panic mode. It’s the sound equivalent of looking into the sun.
Writer Lynn Peskoe-Yang uses this experience as a jumping-off point for a history of LRADs, tracing their use through the Standing Rock protests as well as the 2017 Women's March, before finally offering some advice on how to handle the onslaught of a sonic boom:
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The principle behind using an LRAD as crowd control, rather than for long-distance communication, is similar to the idea behind a whistle or a siren: they all emit tones in the most sensitive range of frequencies for most humans. At a distance, an LRAD deterrent tone may sound like any other alarm.
But while whistles emit sound waves in all directions, LRADs concentrate the waves in a narrow cone of sound, extending about 15 degrees in every direction from the axis, like a flashlight.