If you have a room above a garage and the opener can be heard through
the floor, here's a tip that will make it a lot quieter:

Hang the opener on short (but strong) rubber straps instead of mounting
it directly the ceiling. The rubber will absorb the vibration and
lessen the noise transmitted through the joists.

I used a 3 ply material similiar to a tire (specifically a brake pad
from a Soap Box Derby car!) and the reduction in noise was amazing.

Enjoy!