We also took to the streets to find out what Ottawans heard, and you can check out the responses in the video above.
Story analyzed the acoustic features of the words "Yanny" and "Laurel".
Some Twitter users have said they hear "Yanny" and some say they hear "Laurel".
They said older adults tend to start losing their hearing at the higher frequency ranges. But others have said it's just a simple case of bass versus treble: If you happen to pick up bass tones more, you hear "Laurel".
"But not only that, the brains themselves can be wired very differently to interpret speech", he says.