When the underwater sensors of Raytheon Corporation‘s “swimmer denial” system detect any unwelcome presence, they trigger an underwater sound system that emits extremely powerful pulses of low frequency audio. The pulse rate and audio frequency are chosen to make human organs resonate like organ pipes, causing swimmers to vomit into their masks or suffer internal ruptures.
The idea of blasting powerful sound at underwater targets can also be used to detonate incoming torpedoes.
Raytheon’s main sound projector, in the middle of the secure zone, emits sounds with power and frequency that are relatively safe for marine life. Secondary projectors around the zone also emit safe pulses. But in the region near each secondary projector the main and secondaries combine to produce a sound which is decidedly dangerous.
Would-be spies or terrorists cannot get through the ring but there is no widespread danger to fish, dolphins or whales.
Via New Scientist.