Soundproofing spray foam insulation is also quite effective for use in reducing sound in a room with a cathedral ceiling. First, your expert team will cut panels into the ceiling. The installer then sprays the foam into the ceiling cavities. Next, the drywall is replaced and then a rough coating of drywall mud is applied over the seams. Both spray foam and injection foam fill the cavity where they are added totally. They are both popular choices for superior insulation material for decreasing, but not completely eliminating, exterior noise from your home.