Question

The intensity of reverberation is higher in a closed and empty house.
( give scientific reason)

Answer 1

The reverberation time is larger for an empty hall than for a crowded hall because there are many sound absorbers present in a crowded room, whereas the sound is reacted back by the walls of an empty room. Therefore it persists for a longer time in an empty hall. 

Answer 2

In a close and empty house,there is absorption of sound  only by the floor and ceiling. hence, the intensity of reverberation is higher.