bdp24,
Yes audiology test are, or would be, sobering for many.
I get tested pretty regularly. I'm 55, can hear up to 14k. (Good for my age, no doubt because I've worn earplugs for loud events since the 90's). Slight notch at 4k.
Still, it's surprising how much deviation people's hearing can exhibit while still allowing a surprising recognition of sound quality. I have a musician friend who has some pretty bad hearing in one ear, and just ok hearing in the other, but he's able to hear and describe most of the relevant characteristics of different sound systems.