How good are your ears?

I constantly test my hearing, because I'm a bit neurotic about my ears. I can hear pretty loud and clear up to 18kHz, and somewhat up to 18.5kHz, but above that it's silence, which is not surprising at all for a 23-year-old. While the hearing in both my ears is pretty much equal, my right ear has always been a bit sensitive to loud noise and it starts kinda distorting and crackling when there's too much presence range information. It's always been like that, though, and it's actually a good indicator when mixing live. When the ear starts distorting, I'm mixing too loud :)
 
The test is shit. It must be at a certain volume to be at least a little meainingful. And yes, with crappy speakers you will even hear 21 khz because they output a lot, just not 21 khz. I tried it with shit speakers once and the frequency got lower after like 18 khz, so... :lol:

18kHz in this test and if I crank it a little, 19 kHz. I'm 21.
 
On these shitty speakers my left ear gets up to 15khz and my right ear up to 17khz. The result of 5x surgery on my eardrums I'm afraid. I'm 23.
 
Doesn't the speakers/monitor/cans you listen on affect this? I could hear audible stuff at like 19-20khz, but it was more like "something is there" and when it ended "something is not there". Studio-cans. Just turned 19.
 
Doesn't the speakers/monitor/cans you listen on affect this? I could hear audible stuff at like 19-20khz, but it was more like "something is there" and when it ended "something is not there". Studio-cans. Just turned 19.

Thats why it isn't very scientific. For it to be fair everyone would have to use the same speakers/headphones, capable of producing all the frequencies