I drove a 1980 Kenworth DC 900 tanker that had no in cab insulation of any kind and had a CAT engine. I estimated the sound levels in it at
about 115- 120 decibels plus when under load. Has anyone had one of these and measured the sound levels on it?? I thought it could do permanent ear damage in a matter of weeks if driven for 6-7 hours a day. Am I way off on this??