Question

Why we cannot hear echo produced in the class room?

Answer 1

to produce echo that should be a open place .in a classroom there are many students were making noise so this is a reason we cannot listen echo in a class

Answer 2

$\huge\pink{Answer}$

For distinct echoes, the minimum distance of the reflecting surface from the source of sound must be 17.2 m.

Benches in the classroom are sound absorbing materials which prevent echo of sound.

Because of these two reasons echo is not heard in a classroom.