Given my early history of abusing my ears, I certainly agree with you that there's surely a progressive component to hearing loss. While I can't argue with the experts that any noise greater than 90 db can damage the ears, my exposure to extreme noise as a soldier, hunter and civilian shooter should make me the poster child (read, old fart) for the totally deaf. However, I've often wondered if the human ear's tolerance for noise is higher than they suspect. Like lung cancer, maybe some are more susceptable than others. To this day, 50 years after the event, I can still get away with my high frequency loss except for under certain social circumstances. I tell my wife that I can hear just fine, I just can't understand certain words.