So, here is more information about this Yanny or Laurel thing. The sound recording was not well done, so it has some high frequency echoes of the low frequency sounds. Depending on the speaker system used to listen to this, the gains on the frequencies will be different such that you can hear either Yanny or Laurel. Also, you can separate out the sounds. The low frequency is around 200 Hz, the high frequency is around 3000 Hz to 6000 Hz, which creates an interesting effect as both are at the far sides of human hearing where the perceived intensity will be lower than the middle frequencies. Also, humans are trained to listen for human voices and filter out other sounds, so this also factors into play as to what different people will hear when listening to this. Younger listeners tend to hear Yanny more often than older listeners, for several reasons mentioned above, and the fact that older listeners will have a more attenuated response on higher frequencies compared to younger listeners.
20180518/https://en.wikipedia.org/wiki/Yanny_or_Laurel 20180518/https://www.vox.com/2018/5/16/17358774/yanny-laurel-explained 20180518/https://en.wikipedia.org/wiki/Shepard_tone