Question

define echo???????
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Answer 1

In audio signal processing and acoustics, echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the listener.

Answer 2

Question:-

$\sf\fbox{define echo?}$

Answer:-

An echo is a repetition or imitation of sound. When sound waves hit a hard surface they might reflect, making the sound bounce and repeat. If you agree with someone, you might echo his or her statement.

Given:-

$\sf\fbox{What is echo in science definition?}$

An echo is a sound that is repeated because the sound waves are reflected back. Sound waves can bounce off smooth, hard objects in the same way as a rubber ball bounces off the ground. Although the direction of the sound changes, the echo sounds the same as the original sound. ... But sounds are not always reflected.