Huh. Downloaded a tone generator, and found that while in the video I heard a series of clicks at 16khz and beyond, I could in fact hear 16khz if I raised and l

Huh. Downloaded a tone generator, and found that while in the video I heard a series of clicks at 16khz and beyond, I could in fact hear 16khz if I raised and lowered the volume from nothing to loudest in the app. It sounded like a whine and much harder to hear than I expected, distinguished most easily by when it quickly went from present to not present and back. In fact, I kept going up the scale doing that, and raising the volume, and found that I was able to hear even 19 to low 20khz as a high pitched noise, very quiet even at -6db. So ... yeah, probably does me no good considering that the loudness of other pitches makes it near impossible for me to hear anything practical in those frequencies. Of course, then I go to listen to music and wow, I can hear all this detail. I think I trained my ears for it, or I'm losing it. ;-)