The ear has two important roles. It is our organ of hearing and our organ of balance.
Parts of the ear
The ear is made up of three different parts, including:
How ears hear
Sound waves are vibrations through the air. When we hear a sound (such as somebody’s voice), sound travels along the ear canal and causes the eardrum to vibrate. The vibration of the eardrum causes movement of the three bones in the middle ear. These bones move against the cochlea (the hearing organ) and pass the vibrations to thousands of special hair cells inside it.
The hair cells then send the sound as an electrical signal along the nerve to the brain, where we perceive the sound (our brain interprets the signal as sound).
Ears and balance
Our sense of balance is controlled by signals to the brain from three sensory systems:
The organs of balance in the inner ear are called the vestibular system. This system includes three fluid-filled loops (semi-circular canals) which respond to the rotation of the head. Near the semicircular canals are the utricle and saccule, which detect gravity and back-and-forth motion. When the head is moved, signals from these organs are sent via the vestibular nerve to the brain where they are processed.
The brain uses the information from the inner ear, our vision and proprioception to pinpoint the position of the body.
Some common ear problems include: