U.S. forces are said to have blasted Van Halen music at Manuel Noriega before the ousted Panamanian leader surrendered to them in 1990. In Zero Dark Thirty and the Showtime series Homeland, death metal is used to coerce confessions. But can sound or silence be used not just to annoy but also to kill?
French journalist Juliette Volcler investigates the idea in her new book, Extremely Loud: Sound as a Weapon. In a phone interview, she discussed the science of using sound as a weapon. Here is an edited transcript of her comments.
Q: Can sound really kill?
A: Sonic weapons are nonlethal weapons. They do not intend to kill and sometimes do not even intend to harm, but they intend to stop people — to neutralize them before they act.
Sound is not a practical way to kill someone. You can make a loud sound, but it gets lost in the air. If you can have a loud sound and put it exactly where you want it to be, then it becomes dangerous.
Q: How does that work?
A: The human ear naturally amplifies oral data and the frequency range used by the human voice. It is not a coincidence that the LRAD — "long-range acoustic device," a crowd-control device - projects frequencies belonging to that range.
Acoustic grenades can go roughly from 120 decibels to 190 decibels. German researcher Jurgen Altmann showed that a blast of 210 decibels or more affects the inner organs - the lungs - and could cause internal injury that could lead to death. A blast will impact the body, and would do so very violently.
Q: What about psychologicaleffects?
A: Sounds have meaning. There was research about the psychological effects of sound - sounds like dogs squealing, babies crying, rabbits being killed. Horrid sounds that scare you.
In the 1970s, a U.S. research program called Disperse looked for sounds that would be immediately horrible for anyone. They did not find any meaningful sound that was universally repellent, as sound is culturally biased. The most efficient would in fact be a pure tone like a blasting alarm.
Q: How much of this is science fiction? The CIA isn't building a sonic death ray.
A: A lot of weapons have been dreamed up by defense agencies like the Defense Advanced Research Projects Agency, but they never actually build them. This led to a lot of fantasy stories about sonic weapons, but the failures actually led to the development of a few weapons like LRAD and also to the use of music as a form of terror in, for example, interrogations.
Q: What acoustic weapon scares you the most?
A: Definitely total silence. Sensory deprivation is an extremely violent form of destruction for an individual.