There are various types of acoustic problems that you can encounter in rooms. One of these is due to excessive noise in the room that’s bouncing around and causing echo and another type of interior sound problem could be sound leaving the room and causing problems elsewhere.
The solution for reducing the echo would be to install a sound absorbing ceiling, and the best types of high performance sound absorbing ceiling tiles tend to be the soft rock fibre or glass fibre manufactured by Ecophon and Rockfon.
If the acoustic problem is due to sound leaving the room then one solution would be to install a hard-surfaced ceiling tile which would then reflect the sound back in to the room.
Regardless of which type of acoustic problem you may have, the best solution would be to contact an experienced suspended ceiling contractor who will be able to give you expert advice.