It’s The Dress but for linguistics (from Cloe Feldman on twitter).
A couple explanations of what might be going on. From The Verge:
The secret is frequency. The acoustic information that makes us hear Yanny is higher frequency than the acoustic information that makes us hear Laurel. Some of the variation may be due to the audio system playing the sound, Reicke says. But some of it is also the mechanics of your ears, and what you’re expecting to hear.
Older adults tend to start losing their hearing at the higher frequency ranges, which could explain why Riecke could only hear Laurel, but his eight-year-old daughter could hear Yanny. It’s a phenomenon you can mimic on a computer, he says: if you remove all the low frequencies, you hear Yanny. If you remove the high frequencies, you hear Laurel.
From Rory Turnbull on twitter:
Here's what I think is going on. In the first syllable, there's only one major spectral peak below 2.5kHz. It has a wide bandwidth, which is consistent with an F1 and F2 very close together: an /ɑ/ (for "Laurel").
The higher spectral prominence dips down about halfway through the word, between the two syllables. If the lower spectral prominence is F1 & F2, then the higher one must be F3. A low F3 = /ɹ/!
But what if we treat that higher spectral prominence as an F2, rather than an F3? Then we have a very high F2 in the first syllable, consistent with a front vowel or approximant, e.g. /j/. The F2 stays pretty high and the F1 gradually rises, giving a percept of /jæ/
The fall of the F2 between the two syllables is then consistent with an /n/, although we don't see the general amplitude dampening that we normally associate with nasals. The F2 rises and F1 falls again at the end, resulting in /jæni/ overall.
An earlier example of the Yanny/Laurel phenomenon: BILL BILL BALE BALE PALE PAIL MAYO
