Which remedies should you use to reduce the echo in auditorium ?

Dear student ,
Remedies to be used to reduce the echo in auditorium are :
1. carpets can be put on the floor to absorb the sound .
2. heavy curtains are put on doors and windows to absorb sound .
3. panels made out of sound absorbing materials are put on the walls and ceilings .
Hope it will help you
Regards ,