Question

What is echo?

Answer 1

1. It is a common experience that when we shout in front of a high mountain or a deep well or in a big empty hall, we hear our sound back after a few seconds.
2. This is known as echo.
3. An echo is the repetition of the original sound heard after the sound is reflected from a distant, dense, and rigid object (such as a high building, cliff, etc.).
4. The human ear can hear two sounds separately only if they reach the ear after an interval of 1/10th of a second.
5. This is a natural feature of the human ear.
6. Therefore the reflected sound which can be heard distinctly (after a lapse of at least 0.1 sec) from the original sound is called an echo.