Résumé
The adult mammalian ear is made up of three distinct parts, the external, middle and inner ear, which function as one anatomical unit responsible for both hearing and control of equilibrium ( Figure 1 ). The external ear is the sound-collecting funnel. It comprises the auricle and the external auditory canal which transfer sound to the tympanic membrane. The middle ear transmits the sound from the tympanic membrane to the inner ear and consists of a chain of three ossicles, the malleus, incus and stapes, which pick up the vibrations received by the tympanic membrane and transmit them to the oval window of the inner ear. The inner ear is composed of an elaborate system of endolymph-filled, epithelially lined chambers and canals constituting the so-called membranous labyrinth. The membranous labyrinth lies, bathed in perilymph, within the temporal bone cavities (the bony labyrinth). The sound-processing portion of the membranous labyrinth is the snail-shaped cochlea. Within the cochlea lies the cochlear duct which contains the auditory transduction sensory apparatus, the organ of Corti. The remaining portion of the membranous labyrinth is the vestibular complex, composed of the saccule, utricle and three semicircular canals, which responds to linear and angular acceleration, hence aiding balance.