My father (who until he retired was an engineer specialising in noise and vibration) warned me about the dangers of loud low frequency noise years ago when I first started going to rock concerts. I thought he was scaremongering (and I never got a collapsed lung, though I once had a nose bleed straight after a Tangerine Dream concert - perhaps being right next to the speaker stack wasn't wise in retrospect), but I guess I owe him an apology.