In some countries (e.g.switzerland http://www.suva.ch/home/suvaliv/kampagnen/kampagnen_safer_sound/safer_sound_schall_und_laserverordnung.htm)
there is a law that limits the level of the music played in clubs and bars. This allows you to party without worrying about damaging your hearing. Additionally to that the organizer of the party has to give free earplugs at the entrance.