I have hearing damage in my right ear. It wasn't caused by any sort of loud noise or firearms and I've been dealing with it since I was very young. While guns didn't cause my current hearing loss, I'm now extra cautious to protect myself from additional hearing loss that could be caused by my firearm obsessions.
According to a study by the “American Speech-Language and Hearing Association,” Firearms are at the top of the chart from produced noise levels. They are listed in the graphic below at 140 dB, which is louder than Jackhammers, Jet Engines, Rock Music, and Snowmobiles. When I read this I found it hard to believe but I suppose that we often don't think of firearms as being as loud of some of these other listed things, because it isn't a prolonged noise. We only have to endure the ring of the gun shot for a few seconds which is hard to compare to the ongoing headache of a rock concert.
The fact is that guns are loud and that every precaution should be taken to reduce risks when shooting. Naturally I wouldn't expect a hunter or a law enforcement officer to go about their activities with ear plugs, but when possible we should protect our ears.
I might not have any hearing loss from firearms… but I keep meeting people who do.