The middle ear (or tympanic cavity) is an air-filled cavity within the temporal bone of the skull.

A channel called the Eustachian tube (or canal) runs from the middle ear to the back of the nose. It opens during swallowing and so ensures that the air in the middle ear remains at atmospheric pressure.

Three small bones transmit sound across the middle ear from the tympanic membrane to the inner ear. These so-called auditory ossicles are:

• the malleus (or hammer) – which is attached to the tympanic membrane
• the incus (or anvil)
• the stapes (or stirrup) – which partially covers the oval window at the entrance of the inner ear.