Question

Why cant we not hear echo produced in our classroom

Answer 1

For an echo to produce the distance should be more than or equal to 17.2 m which is not in our classes so we do not hear echo

Answer 2

Hi friend,
We cannot hear the echo produced in the classroom because the room is too small for echo to produced. and for echo the minimum time for sound to be reflected is 0.1 sec , if you were in large place sorrowing by hills or something like that you surely hear an echo of multiple reflection I. e. many times

Hope my answer help to you