Echolocation (O.E.D., on line):

 The location of objects by means of the echo reflected from them by a sound-signal, as of ultrasonic sounds emitted by bats or by man-made devices.


  1944 D. R. GRIFFIN in Science C. 589 (title) Echolocation by Blind Men, Bats and Radar. Ibid., To describe this process of locating obstacles by means of echoes, I suggest the word echolocation. Ibid. 590/1 A radio signal is sent out from the airplane and electronic devices measure the time required for this signal to be reflected back... Finally we have radar, a refinement of the radio altimeter so beautifully perfected that it can echolocate airplanes at great distances by sending out radio waves and picking up the reflected energy returning from the distant aircraft. 1957 New Biol. XXIII. 43 Another theory about moth behaviour, in which sound acts as an aid to navigation, suggests that they use a system of echo-location analogous with that of bats. 1958 Observer 3 Aug. 5/5 The Harvard scientists estimate that the bat's echo-location system is incomparably more efficient for its size, weight and power, than the most modern radar system. 1959 Observer 14 June 5/4 Asdic, another wartime device used for echolocating underwater objects by ultrasonic vibrations, has given us more knowledge about whales. 1964 Oceanogr. & Marine Biol. II. 438 The conversational squeals and echolocating clicks of porpoises.