The ear picks up sound waves and transforms them into electrical signals which travel along nerves to the brain. The signals are interpreted by the brain and connected to other impressions and experiences – the sound is then perceived as loud or quiet, speech, music or a message such as “the phone is ringing.”
The ear has three parts:
Sound waves travel through the outer ear to the eardrum, causing it to vibrate. The vibrations are passed on to the inner ear through the tiny bones in the middle ear (the ossicles). The actual organ of hearing, known as the cochlea, is found in the inner ear. The organ of balance with its three canals is also found in the inner ear. That's why the ear is important for our sense of balance, too.
The outer ear is made up of skin and cartilage. Like a satellite dish, it captures sound waves and passes them on to the outer ear canal. This passageway is kept open – by cartilage at first, and then by bone further along the canal – so that the sound waves can easily reach the eardrum.
The middle ear is an air-filled space that's also known as the tympanic cavity. It is connected to the upper throat by the Eustachian tube. Air moves in and out to balance out different levels of pressure in the outside environment. But germs can also enter the middle ear through the Eustachian tube from the upper throat.
The ear bones are important for hearing. They are called the malleus (hammer), incus (anvil) and stapes (stirrup). The malleus is attached to the eardrum, picking up its vibrations and passing them on to the inner ear through the incus and the stapes.
This transfer through the bones makes the sound waves louder. Once they reach the inner ear, they are picked up by the snail-shaped cochlea. The cochlea is filled with fluid and lined with very fine hairs (hair cells). These sensory cells turn the vibrations into nerve signals, which are then passed on to the brain.
Brandes R, Lang F, Schmidt R. Physiologie des Menschen: mit Pathophysiologie. Berlin: Springer; 2019.
Menche N. Biologie Anatomie Physiologie. Munich: Urban und Fischer; 2023.
Pschyrembel online. 2026.
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