With products like this, you really do want an actual anatomical ear for measurement - often they rely a lot on the rough physics of the ear itself to work right. There is a whole niche corner of the microphone industry for "dummy head microphones" that are basically an an actual model of a head with detailed ears, and are really useful for measuring both how things sound to a human in an open environment and getting measurements of devices like headphones that need a head + ear to work.