|Class 9 Physics Sound||Echo|
When we shout near a mountain, we will hear the same sound again and again with small time interval gaps. This is called an echo. Echoes may be heard more than once due to successive or multiple reflections
The sensation of any sound persist in our ear for about 0.1 s, which means that to hear a clear echo, the reflected sound must be atleast 0.1 seconds after the original sound.