decibil range created by a 3000 hp recip. engine at idle speed?

Question

hearing has been impaired need to know at what decibil range these engines are capable of creating at idle and at full throttle

Answer 1

125 - 160 db depending on some slight variables... altitude (obviously the higher elevation, less air density... thus less noise) and where in relation to the engine to take a reading (doppler effect) Either way it is very damaging to the human ear proper protection should be carried out.