There didn’t used to be. My wife is nurse for an ear doctor who regularly sees IC employees with hearing problems. Most of us nearing retirement age who worked in heavy industry put up with noise levels early in our careers that were unbelievable. Working in a steel mill I had times where the ringing in my ears would last for 2-3 days. OSHA has done a lot in that regard as has cab isolation on diesels. Forty years ago if you asked for hearing protection you would have been laughed out of the office. Today earplugs and micky mouse ears are used all the time. Engines will never be Cadilacs so smart people take precautions in addition to what has been done to minimize the noise levels.
Yes, I’ve noticed that some train crews wear ear defenders…great idea. Reduction in noise pollution is one of those good news stories one never hears about. Heavy machinery was alot noisier 20 or 30 years ago. Maybe the higher horse power ratings also have something to do with it…a pair AC4400CWs to move a train instead of a pair of GP9s beating themselves to death at wide open throttle with sparks flying.
The Occupational Safety & Health Administration’s maximum allowable noise level for an 8 hour exposure without ear protection is 90dBA. However, other agencies can set lower noise levels as the FRA has done.