Diabarman
We can not here an echo in a class room because the sound,after bouncing back, reaches us before 0.1second , and thus it is not heard clearly.(or) the distance is not sufficient .
Payal5690
Because for creating echo we need long distance with high walls as it is in mountain region......while in classroom the area is small and has windows and door .so , the frequency of sound travels all around and goes out from windows and door.
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