Where did Yanny or Laurel come from? Origin of the illusion reveals which word is correct

Just like 'brainstorm or green needle', the correct answer can be found by chasing down the obscure original video

The internet is being torn apart over whether a robot voice is saying yanny or laurel, green needle or brainstorm. But the answer to which one is correct lies in their origins.

Tracing the two strange clips to their beginnings helps decide which of the words is actually the correct one. And it also demonstrates the entirely accidental way that both were created.

Both of the viral video clips erupted over the last few days, as they spread online and people argued about what they said.

First came the "yanny or laurel" video. That was put on Reddit and tweeted and then made its way around the internet incredibly quickly – so fast that Donald Trump responded to it within just a couple of days.

Then came the "green needle or brainstorm" video. That sound relied on the same strange effect, and provoked the same kind of vociferous arguments and fallouts, but was even stranger.

Of course, in one important sense both of the possible words are correct. So long as anyone is hearing them, they are there – and it is possible to alter the sounds so they conclusively say either of the two words.

The trick works because the brain can only hear one of those sounds at once, but the ambiguous nature of the syllables means that they can be heard at least two ways. As such, it's something like an auditory version of the famous duck-rabbit puzzle, in which a drawing can look like either of the animals depending which you think about.

But in another way, there are right answers. Though both of the sounds have been distorted into sounding like something else, their origins can tell us which of the words is correct.

In the case of yanny or laurel, the sound came from a dictionary.com pronunciation guide of the latter word. That sound was then played through computer speakers and re-recorded on another microphone – and the distortion added through that process served to warp some of the sounds, adding the extra noises that now allow people to hear "yanny" as well as the original word.

And as for "green needle or brainstorm", something similar happened. The sound comes from a review of a Ben 10 toy that said the word Brainstorm – the name of a character in the show – that was posted to YouTube in 2014.