In a system, the reduction of the power level of an echo or the elimination of an echo.
Note: Echo cancellation is usually an active process in which echo signals are measured and canceled or eliminated by combining an inverted signal with the echo signal.

A check to determine the integrity of transmission of data, whereby the received data are returned to the source for comparison with the originally transmitted data. Synonym loop check.

A programming language command that causes an echo response from a computer to be displayed on a monitor or printer for analysis or monitoring of the progress of processing.

See ghost.

In computer systems, on a hard-output or display device, a line of information that verifies (reflects) data entered into the computer.

The ratio in dB of the power of a transmitted signal that is echo loss weighted (as specified in ITU-T Recommendation G.122) to the power of its reflected echo. [T1.255-1997]

The maximum echo path delay for which an echo canceler is designed to operate. [T1.508-1998]

The time in milliseconds (ms) between the incidence of a signal and the incidence of that signal's echo at a measurement point. [T1.255-1997]

See return loss.

The measurement of the depth of a body of water or the distance to an object in a body of water by measuring the time it takes sound or electromagnetic waves of known velocity to reflect from the bottom of the water body or from the distant object.
Note: In echo sounding, damped cw transmission is usually used.