Question

what is an echo in the small room

Answer 1

if you want to hear the Echo of your voice or any of the sound from the sound emitting body then your minimum distance from the reflecting surface of sound waves should be 1.7 m if it is less than that then you won't be able to hear the Echo because the sound heard by our ears the sense of this sound 0.1 second

Answer 2

If you have ever been inside a large public space or loft with bare walls and hard surface floors , you may have noticed a distinctive ringing sound called flutter echo . This phenomena occurs when sound waves bounce back and forth between the walls , ceiling and floor making conversation difficult.