How does the ear work? Hearing is an essential sense that we rely on every day for communication and safety. Most people don’t realize how important this sense really is on our day-to-day life. For information on the importance of hearing, check out our previous blog. So, how do we hear? How does the ear really work?
In a normal auditory system, the ear is comprised of 3 distinct sections: the outer ear, the middle ear, and the inner ear. They work together to funnel and capture sound and thus, feed it into our brains. As a result, our brains do all the hard work of understanding.
THE OUTER EAR
The outer ear is the portion that is visible to us and is typically what people will think of when they think of ears. The portion that captures and therefore funnels sound into the pinna. Sounds are airwaves and these are funneled into the ear canal by the pinna. Once the sound is trapped in the ear canal, everything is directed towards our tympanic membrane, or eardrum. The eardrum is a very thin membrane that vibrates like a drumhead due to sound hitting it.
THE MIDDLE EAR
The eardrum marks the start of the middle ear space. This portion of the ear is where we will find the ossicles, or 3 small bones suspended behind the ear drum. Although medical professionals will call these bones the malleus, incus, and stapes, you might know them as the hammer, anvil, and stirrup. The stapes, or stirrup, is the smallest bone in the body! The 3 bones work together to pass the vibration of sound from the eardrum (outer ear) to the cochlear (inner ear). It is important that the middle ear hold air and not fluid. The Eustachian tube works to keep the air pressure equalized so the eardrum can vibrate freely.
THE INNER EAR
The stapes, or stirrup, connects to the final part of our ear, the cochlea. The cochlea is snail shaped and resides in the temporal bone of our skull. The cochlea contains fluid and has 2 parts. The snail shaped half deals with the sound waves and hearing, and the other half contains 3 semi-circular canals which we call the vestibular system. We use the 3 semi-circular canals to maintain our balance and sense of motion in space. If something interrupts the fluid in the semi-circular canals, the person will likely become dizzy.
To hear, we use the coiled portion of the cochlea. Once the sound enters the cochlea, it travels like a wave through the fluid inside the ear. The entire length of the cochlea contains outer and inner hair cells. These hair cells will dance and sway as a result of sound waves passing by. The bundles of hair cells have nerves attached that will therefore fire the signal into the brain.
THE BOTTOM LINE
The important thing to remember about our hearing is that we really hear with our brains. Our ears capture the sound wave and therefore converts it to a nerve impulse. Our brains need constant practice and should not go without sound for too long.
An audiologist can evaluate how all 3 sections of your ear are working, along with the brain. To schedule an evaluation, call (651) 888-7888.