hmm it's definately a problem - when I play out I normally have the headphone volume say on a pioneer mixer on full - and pressed into my ear - I use sony mdr-v700's - got to be bad for your hearing.....however i have played with a lot of pro dj's who do 2 or 3 gigs a weekend every week and I don't ever remember seeing any of them wearing earplugs.....so what must happen to their ears? I guess they must end up like roadies - deaf! the thing about tininntus is only takes a one off event to happen - it's not cumulative....so in just one situation the volume is too loud and there's too much squarewave distortion and you get the damage.....