Middle ear: A part of the ear that consists of the eardrum (tympanic membrane) and, beyond it, a cavity (tympanum). This cavity is connected to the pharynx (nasopharynx) via a canal known as the Eustachian tube. The middle ear cavity also contains a chain of three little bones, the ossicles (the malleus, incus, and stapes), which connect the eardrum to the internal ear. The middle ear communicates with the pharynx, equilibrates with external pressure, and transmits the eardrum vibrations to the inner ear.
