How your hearing works
The outer ear funnels sound down the ear canal to the tympanic membrane (eardrum), which transmits sound vibrations through the tiny ossicle bones into the cochlea. This spiral-shaped organ contains hair cells which send electrical signals to the brain.
Hair cells and the auditory nerve are fragile, and damage to them can result in hearing loss. There is not yet any medical or surgical correction available to repair this damage, and wherever possible hearing aids are the best treatment for hearing loss caused in this way.
The pinna is the visible portion of the ear. It acts as a funnel, amplifying the sound and directing it to the external auditory canal (ear canal).
The tympanic membrane (eardrum) is a thin, semi-transparent, oval-shaped membrane that separates the ear canal from the middle ear.
Behind the eardrum, the middle ear space connects the ear to the nose (via the Eustachian tube) and passes on sound to the inner ear via three tiny bones called the ossicles.
The Eustachian tube allows fluid to drain down the throat and equalises pressure on either side of the eardrum.
The inner ear contains the cochlea, the organ of hearing, which is lined with hair cells.
The cochlea converts physical vibrations into electrical impulses.
Over two million tiny hairs, called stereocilia, pick up the movement of the basilar membrane and cochlear fluid.