When soundproofing a ceiling, identify the types of noise you’re insulating the room from. Generally, nuisance noises are caused by vibrations (also called impact noises) and sounds that travel through the air. Caulk, foam, or rubber treat impact noises by installing a pliable material that absorbs the vibrations. Insulative tape or spray foam insulation treat airborne noises closing any air gaps that could transfer sound.
Another technique involves installing a second layer of drywall. The second layer is installed perpendicular to the first, separated by sound-deadening caulk. Together with soundproofing adhesive, this prevents the drywall layers from touching or sharing fasteners that could transmit sound.