Have you ever wondered why your voice sometimes echoes?
An echo is a sound that is heard after it has been reflected off a surface like a wall. This happens because of sound waves bouncing around! The sound waves hit the surface and then travel back to your ears.
Echoes are often heard in small spaces with hard walls like a well, as these surfaces absorb less sound. You can also often hear echoes in canyons and mountain ranges.
The length of time between the moment you shout and the moment that you hear the echo is determined by the distance between you and the surface that creates the echo.