It can be said that noise coming through a ceiling from neighbours staying above could be a very irritating & difficult to tackle situation you’re likely to encounter. There might be noise travelling through the ceiling in the form of neighbour’s footstep hitting the floor above , furniture being moved or loud music . This large amount of vibration will race through the flooring above and start entering your ceiling . Sometimes the ceilings are not adequate to stop the travelling noise from above so vibration passes through very easily. Another issue to be considered is that your walls are attached to the ceiling above, so the sound created above is also entering your room through your walls. This is known as flanking noise. Not as much sound will come through the walls, however perhaps 5% to 30% of the noise you’re hearing may be coming in through your walls .
Lastly, there are generally holes in your ceiling for lights, ceiling fans and ventilation. There are also possible flanking paths that need to be dealt with
For this high level of isolation all 4 Elements of Soundproofing should be deployed: Decoupling, Mass, Absorption and Damping.
Do I treat the noise from the floor or the ceiling?
When designing any soundproofing solution at the beginning , we would always prefer to treat the noise at its source. This allows us to control and reduce the (sound) vibration before it is originated . If we could treat the floor above to immediately destroy the vibration before it gets into your ceiling things would be a lot easier. With a hard finished floor above, however, this is generally not possible, and most of the time neighbours probably dont want to help in such a situation anyway. So really all you can do is treat the ceiling on your side.