I can do the same thing. It’s fun!
I just wish my tonal range were higher. Some app I just installed says my high is C7 and my low is G#5. What’s that… An octave and a little?
https://f-droid.org/packages/de.moekadu.tuner/
But that doesn’t indicate the range where it sounds the best.
I can focus my eyes to different distances without using the finger trick, which comes in handy never.
I’m assuming you’re talking about convergence. When your eyes are physically turning inward to align on a nearby object, that’s called convergence. Focusing is what your lenses do, although the technical term is “accommodation”.
I’m excellent at controlling convergence, too. I can be looking at my phone screen (like right now) and diverge my eyes just enough to make neighboring letters overlap. Or diverge them so much I see two phone screens entirely. Or anything in between. Same with converging and going cross-eyed.
I can even diverge my eyes slightly further than parallel, making individual stars in the night sky look like two stars. But not by a lot. Looking at me, you’d probably just think was looking in the distance. I can’t make my eyes look in different directions like a chameleon.
This does have one handy use: I can see those Magic Eye posters at will, in a split second, even across the room!
Same, but more like 13k Hz last time I tested myself.
Rat farts.