Can You Hear Me Now?

I was watching VH1 Classic & FUSE this afternoon before breakfast, and the muffled lyrics of various rockers led me to wonder how badly years of blasted classical music & autechre have destroyed my hearing. I am sure there are several metrics that can be used, among which would be ability to distinguish between similar frequencies, and the ability to hear high frequencies.

Figuring that a good first step would be to see what my hearing range tops out at, I googled for "tone generator" and found Mac & Windows software here that let me generate frequencies within the human hearing range. My speakers should at least go up to 20kHz, so I think this is a reasonable test setup.

The Human Hearing Range is supposedly from 20Hz to 20000Hz. My hearing appeared to top out at about 17.3kHz. (That's good, right?) I could feel sounds slightly higher than that, but by 18kHz, I could not feel anything at all. I am tempted to blast my speakers at just above 18kHz just to see if anybody notices. (I've also been tempted to play rodent love songs loudly, but that's another story.)

I suppose that there's a question of the ability of my speakers to produce the high frequencies, but since I could feel the tones, I assume that at least to 18kHz, my speakers do work properly.

What's the highest tone you can hear?

And no cheating!