strict warning: Only variables should be passed by reference in /home/howyourb/public_html/modules/book/book.module on line 559.
1) Sound waves are collected by the outer ear. 2) Little bones (ossicles) focus the sound vibrations onto the cochlea of the middle ear.

3) The basilar membrane inside the cochlea breaks the sound waves up into different frequencies. 4) Tiny hair cells which live on the basilar membrane translate mechanical vibrations into patterns of nerve impulses.

Video credits Med-EL