Ultrasound audibility

An issue with research into high frequency whatevers (not specifically the paper linked above) is that they often use this fuzzy word "audibility" as your defining point or boundary condition, but then they have this wacky broad spectrum of physiological responses that result from ultrasonics and they link it back into the fuzzy audible realm.

Like... stare at a light for a while, your eyes will strain if it's too bright, ok cool that's a quantifiable response. Now lets do a couple short tests at shorter and shorter wavelengths until we're into UV, and hey that's interesting your eye doesn't react anymore. That means we're obviously beyond the visible limit. Now let's shine a bright UV light into the eyeballs, oh would you look at that I can smell smoke. Obviously UV must be affecting our visible sight somehow!

 

That triggered memories of the laser treatment I had to weld my detached vitreous back in place. Thanks

 

FWIW, there's at least one Knowles MEMs microphone that goes well over 100 kHz, maybe as high as 200 khz, and they're not terribly expensive. Personally I can't hear much above 12.5 kHz and have never found ultrasonics, even at high levels, audible. It's also very hard to reproduce them without creating at least some artifacts.