It's definitely a cumulative thing. In my teens there was 3 years of Navy engine room noise. Screaming steam turbines and paint chipping with pneumatic guns. Hearing protection? Ha! You became attuned to the sound of the plant running right. The slightest change in sound was your first clue something was amiss. Throw in plenty of rock concerts, too. In my twenty's I began to shoot my .357 magnum. Ah, ears would ring for a day or so and then stop. No problem.
Then there was 14 years of Army National Guard with M60 mg's, M16 blanks, M85 .50 cal and the mother of all, the 105mm main gun.
It's too late for me, now I'm the guy sitting by himself in a room of people only hearing a buzz and ring.
Being hard of hearing is, however, the only handicap that is still OK to ridicule. Most seem to think that a hearing problem will somehow heal itself from one meeting to the next. "You're deaf as a post!!!!" Yeah, still.
If you are considerate, you change your first words frequently. "Come again?" "Excuse me?" "How's that again?" "Say what?" "Say again, please?" "I'm sorry, I didn't hear you." And the ever popular "WHAT?" etc etc.
Cest la vie, I brought it upon myself for the most part.