Noam Hassenfeld

One of these allusions I love is called the octave illusion.

I wonder if I can play it for you.

Tell me what you hear.

Low on one side, high on the other, right?

Okay, I hear the exact same thing.

The issue is that there is a low note and a high note on each side.

Each ear is getting low, high, low, high, low, high.

They're overlaid over each other.

You think you're just getting low one ear, high in the other, but you're actually getting two sequences of low, high.

And the reason you only hear low in one side and high in the other is that your brain is editing the sequence for you.

Because your brain needs to separate sounds to make sense of them, right?

It has to separate that blobby waveform to pull out the words or the bird song.

And that's what it's doing.

It's pulling out high and low and separating them between your ears.

I really have no idea.

I cannot listen to this and hear the tones in both sides.

Like I just hear low on one side, high on the other side, even though I know that that's not actually what the audio is.

I even spoke to this science writer named Mike Korist, who lost his hearing and then got a cochlear implant.

And it made everything sound kind of weird and robotic.

Like, you ever see that movie Sound of Metal?