sound underwater signal
31warning system — ▪ military technology Introduction in military science, any method used to detect the situation or intention of an enemy so that warning can be given. Because military tactics from time immemorial have stressed the value of surprise… …
32Hydrophone — A hydrophone (Greek hydro = water and phone = sound ) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates electricity when… …
33DragonflyTV — Not to be confused with Dragonfly Film and Television Productions. DragonflyTV Format Children s television series Created by …
34Hearing aid — Behind the ear aid In the ear aid …
35ultrasonics — /ul treuh son iks/, n. (used with a sing. v.) the branch of science that deals with the effects of sound waves above human perception. [1930 35; see ULTRASONIC, ICS] * * * Vibrational or stress waves in elastic media that have a frequency above… …
36Animal echolocation — Echolocation, also called biosonar, is the biological sonar used by several animals such as dolphins, shrews, most bats, and most whales. The term was coined by Donald Griffin, who was the first to conclusively demonstrate its existence in bats.… …
37Albert Beaumont Wood — Infobox Scientist name = Albert Beaumont Wood caption = Albert Beaumont Wood birth date = dd mmm, 1890 birth place = Uppermill, Yorkshire, UK death date = 19 July, 1964 death place = town, country residence = flagicon|UK United Kingdom… …
38Alaska Communications System (ACS) — The Alaska Communications System (ACS), also known as the Washington Alaska Military Cable and Telegraph System (WAMCATS), was a system of cables and telegraph lines authorized by the U.S. Congress in 1900 and constructed by the U.S. Army Signal… …
39Diver rescue — Beaching a casualty while providing artificial respiration Diver rescue, following an accident, is the process of avoiding or limiting further exposure to diving hazards and bringing a SCUBA diver to safety.[1] A safe place is often a place where …
40MythBusters (2008 season) — Country of origin Australia United States No. of episodes 20 (includes 8 specials) Broadcast Original channel Discovery Channel …
