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geoduck

(Encyclopedia)geoduck go͞oˈēdŭkˌ [key], common name of a Pacific clam, Panope generosa. The largest intertidal burrowing bivalve in the world, the geoduck may weigh up to 12 lb (5.4 kg). The shell is thin, lac...

Vancouver, George

(Encyclopedia)Vancouver, George, 1757–98, English navigator and explorer. He sailed on Capt. James Cook's second and third voyages. After 1780 he served under Admiral George Rodney in the West Indies, taking part...

Washington, state, United States

(Encyclopedia)CE5 Washington, state in the Pacific Northwest of the United States. It is bordered by Idaho (E); Oregon, with the Columbia River marking much of the boundary (S); the Pacific Ocean (W); and the Ca...

croaker

(Encyclopedia)croaker, member of the abundant and varied family Sciaenidae, carnivorous, spiny-finned fishes including the weakfishes, the drums, and the kingcroakers (or kingfish). The croaker has a compressed, el...

voice, sound produced by living beings

(Encyclopedia)voice, sound produced by living beings. The source of the sound in human speaking and singing is the vibration of the vocal cords, which are inside the larynx, and the production of the sounds is call...

acoustics

(Encyclopedia)acoustics əko͞oˈstĭks [key] [Gr.,=the facts about hearing], the science of sound, including its production, propagation, and effects. Various branches of acoustics that deal with different aspects...

echo, in acoustics

(Encyclopedia)echo, reflection of a sound wave back to its source in sufficient strength and with a sufficient time lag to be separately distinguished. If a sound wave returns within 1⁄10 sec, the human ear is in...

sonic boom

(Encyclopedia)CE5 Sonic boom wave pattern from a supersonic aircraft and variation in pressure sonic boom, shock wave produced by an object moving through the air at supersonic speed, i.e., faster than the spee...

echo sounder

(Encyclopedia)echo sounder, an older instrumentation system for indirectly determining ocean floor depth. Echo sounding is based on the principle that water is an excellent medium for the transmission of sound wave...

decibel

(Encyclopedia)decibel dĕsˈəbĕlˌ, –bəl [key], abbr. dB, unit used to measure the loudness of sound. It is one tenth of a bel (named for A. G. Bell), but the larger unit is rarely used. The decibel is a measu...