How do earphones create the illusion of sounds playing behind you?

Question

How do earphones create the illusion of sounds playing behind you?

In: 52

Answer 1

You can only “technically” hear things in one dimension – directly to your left and right. We are able to determine spacial sound because our heads, faces and ears _slightly_ obstruct or alter the sound coming from different directions, as well as the ever so slight timing difference between the sound hitting one ear, then the other. Our brains are able to pick up on those slight changes and determine where the sound came from.

We can mimic those changes, either by using binarual recording or with software, so when we listen via headphones, our brains a tricked into performing those spacial assessments on the playedback sound.