The Long Range Acoustic Device (LRAD) produces a 30 degree cone of audible sound in frequencies within the human hearing spectrum (20 Hz - 20kHz). An LRAD was used by the crew of the cruise ship "Seabourn Spirit" in 2005 to deter pirates who chased and attacked the ship. More commonly this device and others of similar design have been used to disperse protesters and rioters in crowd control efforts. A similar system is called a "magnetic acoustic device". The Mosquito sonic devices have been used in the United Kingdom to deter teenagers from lingering around shops in target areas. The device works by emitting an ultra-high frequency blast (around 19–20 kHz) that teenagers or people under approximately 20 are susceptible to and find uncomfortable. Age-related hearing loss apparently prevents the ultra-high pitch sound from causing a nuisance to those in their late twenties and above, though this is wholly dependent on a young person's past exposure to high sound pressure levels.