the illusion is it's perceived as the "same" note/tone. It's not, and when you dig, you can tell it's not, but when you're casually listening, your brain here's a "fuller" note for some reason. The "fuller" comes from the two octaves being played simultaneously in your seperate ear holes.
Like sleight-of-hand, you know it's there but you can't quite discern it at the time and are gladly surprised by it but you know it's not real magic.
This sounds like it might be conflating stuff like vibrato (human-fast variation in pitch) or even faster. The illusion in the post and on the Wikipedia page involves changing the tone only four times per second, there's no claims at all about both tones blending together or producing only a single note.
Both are quite clear about different ears hearing different things, and hearing two or more tones.
I’m referring to the perceived sounds. They aren’t blended together. I’m fully aware of what vibrato is and what the post is talking about in terms of changing tone, half tones, auditory phantoms, trichords, and the octave illusion. The Wikipedia page details the phenomenon with stepping and alternating but it’s not the end of it. Various intervals have been tested. Us musicians have been playing with this for a while now.
Like sleight-of-hand, you know it's there but you can't quite discern it at the time and are gladly surprised by it but you know it's not real magic.