135dB, i think, is the threshold for pain. most concert levels are around 110-115 dB. of course if you get to the stacks it could be louder. I used to have a chart that said how long the human ear could undergo such high SPL's before hearing damage at different loudness levels. At the threshold of pain damage is instantaneous. at concert levels, i think our ears can only handle like 20-30 minutes before damage ensues.
as a side, geeky note, I measured the SPL levels of our dryers at the carwash. from 60ft outside of the tunnel it was still 80dB. standing at the center point of the dryers it was 100dBs. When i put the measurment omni in the motor part of the dryer it was 140db's.....whoa
so yeah.....wear earplugs
