What makes an ECHO?
If you shout or clap your hands in a canyon, the sound may make an echo. An echo is a sound that we hear after it is reflected, or bounced back, from some large obstacle.
When you call out in a canyon, the sound waves of your voice travel through the air in all directions. Some of the sound strikes the hard, smooth surface of the canyon wall and comes bouncing back like a rubber ball.
A moment later, these reflected sound waves reach your ears, and you hear an echo of your voice.
The sound waves may bounce from wall to wall, producing several echoes.
Echoes don’t last forever. An echo becomes fainter each time until, finally, you can no longer hear it.
An echo isn’t clear in a large room because the sound bounced back so quickly from the walls and ceiling that it mixes with the original sound. You just hear extra noise. That’s why big, empty rooms are often noisy. – Dick Rogers