The mosquito files are just as fishy today as they were when posted over a year ago in a similar thread. Though I can hear their supposed 22khz clip, I do not for a second believe it to truly be 22khz. Since my audiologist tested me as hearing to 19k, I voted "no," even though with these tests the answer is "yes."
Up to 19khz, there is an obvious increase in pitch between the tones. After this, the pitch seems to almost go DOWN - I'd be willing to wager that the sound we are hearing is some kind of artifact from file creation, compression, playback, etc., and not the actual tone