The ear has three main parts: the outer (the part that can be seen), middle and inner ear. 

The outer ear has the auricle (or pinna), the cartilage external part of the ear, and the ear canal. The ear canal is around 2.5cm long, and runs from the outer ear to the eardrum and middle ear. Earwax is secreted in the canal.

Sound waves cause the eardrum (tympanic membrane) to vibrate. The middle ear is an air-filled space behind the eardrum that contains tiny bones that move with the vibrations. 

The Eustachian tube is also in the middle ear; this has a role in making the pressure in the ear on both sides of the eardrum equal. 

The inner ear contains the cochlea (which transforms the sound waves to electrical impulses) and the vestibule (with passages that contain fluid and help keep the body’s balance).