Question

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

Answer 1

sound ka gunjana echo khlata h
factor affecting echo
have a minimum distance of 17.5 m

Answer 2

An echo is a sound wave reflected from a reflected surface at a distance from the listener.
No echo is heard if the reflecting obstacle is less than 17 m away from the source. An echo cannot be heard in a small room.
I hope this help you friend