Perceptual bias

Your eyes change what you hear#

Anytime I talk about psychological biases I love to bring up the McGurk effect. You watch a clip of someone saying "bar". Then the picture changes to someone mouthing "far", and you hear "far". The sound hasn't changed. In every clip you are only ever hearing "bar".

That is established science, not a theory I'm chucking out there. And it isn't just people describing things differently. What you see changes what you actually perceive. So when you look at a big analogue unit, a vintage interface or a brand name while you listen, it can change what you hear. How much more of a big effect do you want than a literal change of word?

The interface is part of the sales pitch#

Plugin developers often go to great lengths to make their interfaces look like old analogue gear, because they know visuals influence what people hear. If it looks like a channel EQ from an old console, you'll think warm, old, vintage. If it looks futuristic, you might think precise and modern. If it has no interface at all, you might think cheap and crappy. They could all be the same EQ.

The other reason EQs seem to sound different is mundane. Frequency and gain are calibrated the same on practically every EQ, because anything else would be a design failure, but Q is implemented differently, so the same knob value draws a different curve. If you match the curves, the difference goes away. More on that in EQ and plugins.

You hear what you paid for#

Price, looks and labels shape perception. "Made in USA" against "Made in China". A beautiful box against an ugly one. If you've spent a lot of money on something, your brain wants to justify it, and if you've spent hours reading forum posts about how magical it sounds, your ears will hear the magic.

The hi-fi world writes hundreds and hundreds of reviews describing DACs as creamy, lush or ethereal, but in a blind test, people can't hear the difference between two of them. Either some of those reviewers don't know what they're talking about, or they're getting sponsored.

Adjectives often follow expectation#

In my blind compressor comparisons, some people said A had a warmer low end and sounded fuller and nicer, so A must be the expensive emulation. A was my free plugin with a bit of distortion on it. The adjectives tended to go to whatever people expected to be premium.

Blind testing removes all of that. People get noticeably more careful with their opinions when they don't know which one is which, because if you call the free one "warm, lush, open and sweet" and pick it over the expensive one, you look silly.

Experience does not make you immune#

Researchers who have studied the McGurk effect for decades still get fooled by it. Illusions fool the people who discovered them. So a veteran engineer saying "I've got experience, I just know" is no real protection. Experience helps you predict what a move will do. It doesn't switch off your perception.

That is why I still gain match my own decisions, and why every comparison needs controls rather than gut instinct, whoever is doing the listening.

Bias changes the playing, not just the listening#

When I recorded with different drumsticks, the heavier ones felt sluggish and chunky in the hand. Watching the footage back, my hand was moving less with the big sticks, and in one clip I was literally late on the snare. Maybe I was psychologically biased, despite my best efforts to play the groove the same every time. But I think that's just part of it: the heavier sticks are slower in the hand and I don't get as much whip out of them. Either way, part of what you hear in that recording is how the stick changed my playing, not only how the stick itself sounds.