The correct is Reverberation. A reverberation is created when a sound or signal is reflected causing a large number of reflections to build up and then decay as the sound is absorbed by the surfaces of objects in the space – which could include furniture, people, and air.
You multiply the high length and width and if your using centimeters then divide by 500 and then there's your answer.hoped this helped.
you're most likely to find Bedrock