Your ear is made up of three parts – your outer, middle and inner ear. The organ which actually ‘hears’ is called the cochlea, which is located in your inner ear. The cochlear is filled with fluid and contains thousands of sensory hair cells which are attached to a gel-like membrane.
Sounds are actually vibrations, or sound waves, that reach each of your ears at slightly different times, enabling you to locate where the sounds are coming from.
Your pinna funnels sound waves into your ear canal. These sound waves travel along the canal until they hit your eardrum and cause it to vibrate. As a result, three tiny bones called ossicles (the three smallest bones in your body) start moving and pass the vibrations on to a thick layer of tissue at the entrance to your inner ear – the oval window. This, in turn, sets off wave-like motions in the fluid inside your cochlea. The motion squashes the sensory hairs against a second membrane. This movement is translated into nerve impulses and directed to your brain which interprets the sounds so you understand them.