Yanny vs. Laurel spotlights our brains’ desire for filling in the gaps

It's the auditory debate taking the internet by storm. The PBS NewsHour's Nsikan Akpan and Julia Griffin explain how one sound can create two different experiences.

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And now to our "NewsHour" shares,
something interesting that caught our eye.

Yanny vs. Laurel, it's the auditory debate
taking the Internet by storm today.

"NewsHour"'s Nsikan Akpan
and Julia Griffin

explain how one sound can create
two different experiences.

The Internet has been set ablaze
over one sound and two words.

(SOUND PLAYING)

So, which did you hear,
Yanny or Laurel?

This audio clip, which first went viral on
Reddit and then Twitter, features a robotic

voice saying a specific word, but people's
perceptions of that word differ dramatically,

even in the "NewsHour" office.

Yanny.

Laurel.

Yanny.

Yanny.

Laurel.

Laurel.

(CROSSTALK)

How is it possible people are
hearing different things?

The sound is what's called an ambiguity illusion,
and it's nothing new to neuroscientists.

Remember the dress from 2015?

Some people swore it was gold
and white, others black and blue.

That viral photo is a visual
version of an ambiguity illusion.

When a human brain encounters
something it can't immediately understand,

it tries to fill in the gaps.

In the case of Yanny v. Laurel,
the frequency, or pitch, of the sound clip

is cryptic to our minds.

The original poster of the audio clip, an
18-year-old Reddit user from Lawrenceville,

Georgia, recorded the pronunciation of Laurel
off Vocabulary.com through his speakers.

That distorted the sound.

This muddled sound causes our
brains to fall back on their natural preferences.

JULIA GRIFFIN: Folks who prefer
lower frequencies hear Laurel,

while those who lean toward
high frequencies hear Yanny.

This might explain why children
are reportedly hearing Yanny.

The human ability to hear higher frequencies
fades with age.

Your speakers or headphones
may also be to blame, as some sound systems

are tuned to emphasize different frequencies.

People discussing the sound
around you can also shift your mind's perception.

Ambiguity illusions typically
cause our perceptions to land one way or the

other.

Yanny/Laurel and the dress stand
out because they clearly split a room.

But the neurological basis
for exactly why is still a mystery to scientists.

For the "PBS NewsHour," I'm Julia Griffin.

And I'm Nsikan Akpan.

And I don't know
what the fuss is all about.

It's Laurel.