The crew of a luxury cruise ship used a sonic weapon that blasts earsplitting noise in a directed beam while being attacked by a gang of pirates off Africa this weekend, the cruise line said Monday.More [Wikipedia, Long range acoustic device]:
The Seabourn Spirit had a Long Range Acoustic Device, or LRAD, installed as a part of its defense systems, said Bruce Good, a spokesman for Miami-based Seabourn Cruise Line. The Spirit was about 100 miles off Somalia when pirates fired rocket-propelled grenades and machine guns as they tried to get onboard.
The equipment can emit sound in a 15 to 30° beam from a device 33 inches (838 mm) in diameter. At maximum volume, it can emit a warning tone that is 151 decibels (1000 W/m²) at 1 metre, a level that is very capable of permanently damaging hearing. At maximum volume, it can emit voice at a level of 120 dB at 1 metre. The design range extends 300 to 500 metres. At 300 metres, the warning tone is 105 dB.Tags: lrad, military, technology