Sound Thinking (My First Encounter With An Auditory Illusion)

 I'm sure I wasn't alone as a child in trying to work out if a clock actually went "tik tok", or just "tik", by seeing if I could alternate in my head on what beat the "tik" fell, but for me the results never proved conclusive, perhaps because this test specifically depends on skewing the results. Anyway, I knew the mind can play tricks, but I don't think I'd ever encountered a purposefully engineered auditory illusion until today, so huge thanks to Gavin Brockis for the following. It got me very excited.

 According to the youtube blurb the Shepard Tone "seems to continuously get higher but never really does", like the aural equivalent of an Escher staircase, but the mechanics of hearing are far more of a mystery to me, so I'm far less clear what's going on – Oh wait, it's here – Of course Vsauce made a video about it. Further thanks, though, to Gavin for this neat introduction to the reading of sound waves, and to James Bachman for trying to explain it all to me in terms of a slinky, almost as if the slinky was specifically designed to explain waves. Oo. Slinky physics. That's got to be a thing, no?