Olfactory Overload Causes White Smell

Scientific American

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Your morning coffee. A baking pie. That turkey in the oven. There are some smells you just can’t get enough of. But mix them and other scents all together and you get, well, nothing much.

According to a new study, a mash-up of 20 or 30 different odors gives you something entirely nondescript: almost a non-smell, if you will. The finding appears in the Proceedings of the National Academy of Sciences. [Tali Weiss et al., Perceptual convergence of multi-component mixtures in olfaction implies an olfactory white]

If you’ve ever taken physics, you might remember that combining colors of many different wavelengths generates light that’s white. And blending sounds of many different frequencies produces white noise.

Well, researchers got to wondering whether there’s an equivalent phenomenon for olfaction: call it ‘white smell.’ So they whipped up various combinations of 80 distinct chemicals and had volunteers take a whiff. When the olfactory ingredient list topped 30, one cocktail smelled pretty much the same as any other, even when the mixtures didn’t have a single ingredient in common.

The scent was not unpleasant. A professional perfumer called it “aromatic,” which is like saying that the light was, well, light. So enjoy the smells of the holiday season. But try not to sniff too many at once.

—Karen Hopkin

[The above text is a transcript of this podcast.]

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