[Zeke]

I guess I don't have the high sensitivity, but I can't stand the rattling of paper bags when all else is quiet. I have more than a little tinnitus, but I can hear a pin drop when all else is quiet. So under that circumstance, I can be more sensitive.

Denis, I understand a bit more about how griding metal may affect you. It is a nasty sound without a lot of ear protection. In close proximity it may sound a lot louder than it actually is.

As HD said, we all have different harmonics. Let me add that we all have different thresholds as well.