Soundproofing a ceiling is usually considered when unwanted sound been transmitted through a ceiling becomes intolerable and with the increasing trend of replacing carpets with hardwood floors. This leads to more unwanted noise generated from the hardwood.
There are two aims for soundproofing a ceiling; you want to prevent sound from entering or leaving a space or you want to eliminate impact noise from the room above you. You could have noisy kids or neighbours generating a lot of noise, a light ceiling can allow a lot of unwanted sounds to be transmitted into your home. To solve this problem, you should soundproof your ceiling to reduce the transmission of unsolicited sound.