Usually condo buildings have rules about quiet hours - say maybe 11pm to 7am. So a carefully worded letter to the condo assn would be in order.

We once had a problem like this where we ended up gluing acoustical ceiling tiles right on to the wall adjoining the unit next to ours. Wasn't so attractive but it did seem to muffle the noise considerablly. Putting it on the ceiling "where it belongs" might not be so ugly. Lowes has 2x4' panels at about $41. for 80sf. How big is your room? You'd need the adhesive too and a trowel but that should not be so expensive.