How Do We Hear?

Better understanding of hearing loss begins by understanding how we hear.

• Sound waves enter the outer ear and channel along the ear canal to the eardrum.
• The impact of the waves on the eardrum creates vibrations, which are transferred through a series of three tiny bones.
• The third of these bones is connected to a delicate, snail-shaped structure called the cochlea. The cochlea is filled with fluid and lined with thousands of microscopic hairs.
• The vibrations are transmitted to the fluid inside the cochlea, where the hairs are bent by the wave-like action of this fluid. The bending of these hairs sets off nerve impulses, which are then passed through to the central auditory nerves.
• The auditory nerves carry the signal to the primary auditory cortex, or hearing centre of the brain, which translates the impulses into what we perceive as ‘sound’.