Question

Echo is experienced more in a newly constructed room than in a furnished room

Answer 1

Echo is basically a reflection of sounds when it hits an obstacle during propogation ( travel in a straight path).During such reflections a part of the sound is absorbed by the medium itself before giving it back.

A newly constructed room is almost always empty with just the walls,floor and roof contributing for the reflection. But a living room has a lot of furniture and other entities in them to absrob the sound more.

That is why echo is more obvious in a newly constructed room.

Answer 2

Reverberation. Assuming the sound level of the sound source is the same in both cases, in a newly constructed (or old, for that matter) room that has hard walls and floors without furnishings allows the sound to bounce around and linger in the room until it is eventually absorbed by the air molecules. Since the sound lingers, this “reverberant sound energy” adds to the on-going sound energy, raising the overall sound level. In a furnished room, the sound is quickly absorbed by the furnishings and does not linger.

Hope it helps☺☺

Regard
@Yusuf