I wouldn't worry about the noise. You didn't say when you were cruising but if its an Alaskan cruise, the noise will NOT be a problem. The Alaskan cruise on the Spirit was very sedate compaired to our Caribbean cruises. I ask the casino host (who was our Casino host on the Conquest) if that was normal and he said yes... Different crowd I guess. But even in the Caribbean, the Lido deck bar is not one of the louder areas of the ship anyway and you will most likely not hear anything.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007