If you somehow haven't already over the last few days, listen to this audio recording right now. What do you hear? Is the person saying "Yanny" or "Laurel"? If you heard the second answer, you're technically correct. But more importantly: Here's the backstory of where the audio clip came from—and how it went viral—down to the person who recorded it.

There are a few partial explanations for how Yanny and Laurel became 2018's version of "the dress," which similarly tore the internet apart three years ago. The now-infamous audio recording itself originated on the resource website Vocabulary.com, under the entry for "laurel," defined as a "wreath worn on the head, usually as a symbol of victory." And a number of publications have traced the meme back to Reddit, where the user RolandCamry posted it to the subreddit r/blackmagicfuckery, a forum for discussing unbelievable natural phenomena. The meme was then picked up on Twitter by Cloe Feldman, a popular YouTuber with over 610,000 subscribers.

But Yanny and Laurel didn't actually start on Reddit. Like any good meme, it started with teens.

On May 11, Katie Hetzel, a freshman at Flowery Branch High School in Georgia, was studying for her world literature class, where "laurel" was one of her vocabulary words. She looked it up on Vocabulary.com and played the audio. Instead of the word in front of her, she heard "yanny."

"I asked my friends in my class and we all heard mixed things," says Hetzel. She then posted the audio clip to her Instagram story. Soon, a senior at the same school, Fernando Castro, republished the clip to his Instagram story as a poll. "She recorded it and put it on her story then I remade the video and posted it," Castro says. "Katie and I have been going back and forth and we both agree that we had equal credit on it."

Reddit user RolandCamry, a friend of Castro's, says he then took the video from Castro's Instagram and posted it to r/blackmagicfuckery. "I originally saw it on an Instagram story," says RolandCamry. "From there I put it on Reddit."

That explains how Laurel and Yanny went viral. But where did the audio clip actually come from? While many have speculated that it was computer-generated, the reading was actually recorded by an opera singer in New York in December of 2007.

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"It's an incredible story, it is a person, he is a member of the original cast of Cats on Broadway," says Marc Tinkler, the CTO and cofounder of Vocabulary.com. He says that when the site first launched, they wanted to find individuals who had strong pronunciation, and could read words written in the international phonetic alphabet, a standardized representation of sounds in any spoken language. Many opera singers know how to read IPA, because they have to sing in languages they don't speak.

"We hired a bunch of opera singers to record 200,000 words, basically," says Tinkler. He didn't want to reveal the pronouncer's name, since he doesn't know if they're comfortable potentially becoming a viral star. The same person recorded more than 36,000 words for Vocabulary.com, according to Tinkler. He added that his favorite word spoken by the same person is "audacity."

Tinkler says he doesn't know exactly why people hear different things when they listen to the recording, but that it might have to do with the fact that the word is said without any other context, meaning it's not part of a full sentence. "We set [the singers] up with laptops with really great microphones in a DIY sound booth. They would just sit there and a word would appear on the screen and they would say it. They did this thousands of times."

'We hired a bunch of opera singers to record 200,000 words, basically.' Marc Tinkler, Vocabulary.com

Thankfully, scientists have an explanation for why people hear different things when they listen to the recording. A number of academics chimed in to explain the phenomenon on Twitter. They said that the clip is an "ambiguous figure," or as one auditory neuroscientist explained it to The Verge1, the audio version of "Rubin's Vase," an optical illusion where two people's profiles can also be seen as a flower vase. In other words, it's an optical illusion, except for your ears. There's not really a correct answer either way. The reason that the recording is so contested is likely because it's noisy, meaning there are lots of different frequencies captured. What you hear depends on which frequencies your brain emphasizes.