Head phone

Before we get into how headphones work, I'd like to share a quick note on what sound is and how humans hear it.

Essentially all sounds are just vibrations in the form of changes in air pressure originating from a source ( e.g. a stereo or a clap). Our eardrums pick up these slight air pressure changes and interpret them as sound. The two main ways our ears interpret differences in the air pressure changes include pitch and volume. Pitch is basically how fast the changes in air pressure are received and volume is how large the changes in air pressure are that we receive.

Ok, so how do Headphones (aka miniature speakers) send sound to us?

Headphones convert an electrical signal from an audio source device into those air pressure changes we just talked about.