They don't— the air is linear (except at insane sound pressures) so there is no interference. While the ear is not linear, it doesn't respond at those frequenci

They don't— the air is linear (except at insane sound pressures) so there is no interference. While the ear is not linear, it doesn't respond at those frequencies. If it really worked that way it would be trivial to demonstrate. Alas, it doesn't.