If for one reason or another you don’t have access to a floor above to install sound proofing, then you could consider installing a suspended ceiling.
This can provide good sound insulation in flats, particularly those with high ceilings where the reduction in height is not an issue. IT has to be said howver that a suspended ceiling may only reduce the height of the room by less than 50mm.
Installing a suspended ceiling to insulate your room against sound will require acoustic mineral wool, which is highly effective against airborne sound and you will also need to separate the plaster ceiling from the joists above. This will provide protection against impact noise such as footsteps from above.
If you are experiencing noise from above, then you may also find that there is very little gap between the ceiling and the floor above. To increase the gap you can install resilient bars which can be screwed in right angles against the joists.
Before attempting to install a suspended ceiling, it is advisable to hire a specialist sound insulation company. The work can be messy, particularly when you are having to remove plasterboard and then install mineral wool between joists. If work isn’t done correctly you may even lose the natural soundproofing provided by the existing plasterboard.