My 20 year-old daughter just had me listen - I hear Yanny - so there goes my theory on it being the higher frequency thing!
She said something like “Well - like DesCartes said ‘I think, therefore I am’. The only thing we can be sure of is the thoughts we are having - all of our senses might just be tricks and presenting an illusion to us.” I suppose, but I doubt it.
Sadly, I agree that our brains have the ability to interpret what we see and hear and feel. I don’t like it, because it means we cannot always believe our lying eyes.
In this case, I go with those who think this sound is illusory in the sense that it is close in many people’s experience to sounding like either of the two choices. So our brains pick one or the other. I never heard the Y sound, but my wife hears both at different times and so I have to believe her mind is having trouble catching the same sound each time.