I'm pretty sure my hearing has suffered from too much volume throughout my life. From rock concerts, music at home, drag races, etc... I'm in my late 50's now.
In tuning my system using Hi-Fi test CD's, I found that I apparently don't hear much above 10-11 Khz. I'm almost ready to just chuck the tweeters as unnecessary.
On the plus side, my hearing seems resonably sensitive to the frequencies that I can still hear.
I also picked up a Galaxy CM-140 SPL meter not too long ago, and discovered that I often listened to my speakers at up to 85 db or so, which seems quite loud. My wife can't tolerate it at that level. Of course she also can't tolerate it when I run the test CD up past 11 Khz either, and I'm asking her in disbelief "You can hear that?" as she's screaming at me to turn it down.
One thing I've noticed lately, is that as my music system has improved, to sound more accurate, I haven't felt the need to use as much volume.
And with my recent addition of headphones, the volume has been kept very moderate. Hopefully I can save some of the hearing I have left.