Question

what is an echo ?what factors are important to get a distinct echo?

Answer 1

Echo is repitition of sound which comes when the sound produced by us, get reflected when collide with an object. The important factor is that echo could only be heard if the reflecting object or surface is at least 17.2m away from the sound producing object. The echo is heard only if sound takes 0.1 sec or more to reflect from the reflecting surface.