I listened on my laptop through the speakers and could only hear 'Laurel' to the point that I thought everyone was making 'Yanny' up (what is that anyway?!).
I went to see another colleague to tell her about it and she listened to it through her headphones. She could only hear 'Laurel' but as she was playing it through the headphones I could hear 'Yanny' which freaked me out.
It is to do with how you hear the frequency/pitch but I am not sure whether how you listen affects it too, i.e. bassy speakers sound 'Laurel' but higher pitch headphones sound 'Yanny'.