วารสารปี-40-ฉบับที่-4-resize

เอื้อมพร มัชฌิมวงศ์ 231 วารสารราชบัณฑิตยสภา ปีที่ ๔๐ ฉบับที่ ๔ ต.ค.-ธ.ค. ๒๕๕๘ Abstract Long Range Acoustic Device Auemphorn Mutchimwong Faculty of Environment and Resource Studies, Mahidol University Long range acoustic device or LRAD, a kind of non-lethal weapons, is able to emit loud sound at high frequency over a long distance. LRAD can be operated in two modes: (1) Voice mode for communication with target group (2) Tone mode for control target group. Noise emissions from LRAD can cause temporary hearing loss or, in worst case, permanent hearing loss. In addition it may cause feeling unwell, i.e. headache. Currently, government agencies in several countries purchase LRAD for protest control. Before LRAD will be activated to disperse demonstrators, prior warnings should be given. Operation under continuous emission of sound beam must be avoided. Protesters should stay away from LRAD or use hearing protection device. Keywords : long range acoustic device, LRAD