That’s not entirely true anymore. Sound engineers did lots of experiments with microphones placed in the ears of plastic heads, and as a result, we know the modifications that need to be made to a sound to make it seem like it’s coming from so specific point when played through headphones. It works with both over-ear and in-ear ones and works well (despite what the other poster said) as pinna squiggles are accounted for and it turns out that humans don’t need their own personal pinna shape for it to work.

You can find impressive demos by searching for binaural sound, both from microphones in a plastic head or with simulated HRTF.