How hearing works
The ear is the organ that detects sound and that helps us to maintain balance. It is made up of three parts: the outer ear, the middle ear and the inner ear.
The ear is made up of three parts:
The outer ear – receives sound and detects direction
This consists of the pinna, the visible part of the ear, and the external auditory canal or meatus. No two pinna are alike. The function of the outer ear is to gather the sound. Its shape also helps you detect where a sound is coming from.
The middle ear – transforms sound
This is made up of the eardrum and the ossicles. The eardrum, or tympanic membrane, is connected to a chain of three small bones: the malleus, the incus and the stapes. These connect the eardrum to the inner ear. The function of the middle ear is to transform the sound so it can be easily detected by the inner ear.
The inner ear – sends signals to the brain
The inner ear consists of a sensory system that detects the position of the head and contributes to our sense of balance, as well as organs from the auditory system. The auditory organs are located in the inner ear, in the cochlea. The cochlea is shaped like a snail and filled with fluid. Floating in the fluid is the basilar membrane that vibrates in response to sound. Specialised hair cells are embedded in this membrane and connected to the nerve fibres of the auditory nerve. A functioning cochlea converts mechanical sound waves into electrical impulses that are transmitted via the auditory nerve to the brain.
People are our starting point
A cochlear implant (CI) system transforms acoustic sounds into electrical stimulation for the auditory nerve.