How does the ear work?

The ear picks up sound waves and transforms them into electrical signals which travel along nerves to the brain. The signals are "decoded" and interpreted by the brain. The sound may then be perceived as loud, quiet, speech, music or a message such as "the phone is ringing".

The ear has three parts:

• the outer ear (visible part, called "auricle" or "pinna", and external auditory canal)
• the middle ear (the eardrum or "tympanic membrane" and the tympanic cavity containing tiny ear bones. These are called the hammer, anvil and stirrup, or "ossicles")
• the inner ear (cochlea and the organ of balance, called the "vestibular system")

Sound waves reaching the outer ear cause the eardrum to vibrate. The vibrations are passed on from the middle ear to the inner ear. This is where the actual organ of hearing, the cochlea, is found. Fine hair cells in the cochlea play an important role in converting the sound waves into electrical signals. The organ of balance is also found in the inner ear.

© IQWiG (Institute for Quality and Efficiency in Health Care) Last update of this website: 05/22/2012