After the membrane is mounted, free space forms between it and the main ceiling plane. It can be used to place communications. But in our case, it will be much more useful to fill it with some kind of noise insulator. For example, with a foam or mineral wool. Similar materials in construction stores in bulk: just choose your favorite. Great if it is non -combustible (class m2) and environmentally friendly. Here, by the way, you need not to overdo it with the thickness of the insulator. Remember that the thicker it is, the lower the ceiling in the room!