Is there anything I can do to add some sound insulation.

Yes, it is called "space" or "distance". You add it by buying your own
single-family home. This is one reason people find suburbia desirable:
separation and privacy from your neighbors. Trying to change your
apartment neighbor's habits, or to insulate yourself, do not work.

Some people are happy with close quarters, the rest of us move to the
'burbs.