Oftentimes, we think of our ear as one part of our body. They’re just…our ears. But the human ear is actually comprised of 3 primary parts, and all three parts of our ear need to be functioning appropriately for us to hear our best. Our ears are the pathway sound takes as it travels to our brain – let’s explore the ear together.
The first part of our ear, the part that we can see, is called the outer ear. This includes the parts of the ear that are visible on the outside of our heads – it includes many different landmarks, but the pinna, the concha bowl, and the earlobes are the most prominent areas of the outer ear that we can see. The outer ear also includes our ear canal, which leads all the way down to our eardrum. This is the part of our ear where our earwax is made. Within the ear canal, we have two types of glands that contribute to the production of earwax; sebaceous glands, and modified sweat glands. Earwax is a natural mixture of the secretions produced by these glands combined with dead skin cells (keratin), shed hair, and bacteria.
Earwax is completely normal and generally not a problem – as skin cells within our ear canal shed, earwax will oftentimes work its way closer to the entrance to our ear canal, dry up, and fall out of our ears during our normal daily activities. Earwax is only produced in the outer portion of our ear canal (not deep or close to the eardrum), but sometimes it can get pushed deeper into our ears or accumulate so much that it causes a blockage which can prevent sound from appropriately traveling through the outer ear. Your ears are actually pretty efficient at cleaning themselves – the use of q-tips or at home cleaning is generally not necessary! But, if you or someone you know does need to have earwax removed, it’s generally best to have this completed by a professional who can see the ear canal while they’re removing the wax to prevent wax from getting pushed deeper into the ear. Having a professional clear your ears will also minimize the risk of injury to the ear canal during removal. The outer ear ends at our eardrum, which is a very thin membrane that vibrates in response to sound energy. When the eardrum can move appropriately, it helps to transfer the acoustic sound from outside of our heads into a mechanical vibrations that then travel through the rest of our ear.
Beyond the outer ear, we have our middle ear. The middle ear is an air-filled cavity located behind our eardrum, which is connected to our nose and throat system by something called our eustachian tube. The eustachian tube is meant to help regulate ear pressure, drain fluid, and prevent infection from spreading from the throat to the ear. If the eustachian tube is not functioning properly (which can happen in the case of colds or allergies), it can lead to pressure and pain in our ears. Within the middle ear space, we also have 3 small bones that are collectively referred to as our ossicles. The ossicles include the malleus, the incus, and the stapes (or you may have learned them as the hammer, the anvil and the stirrup). They are the smallest bones within our body, and they are responsible for transferring the acoustic sound energy that travels through the outer ear into mechanical sound energy as the bones vibrate in response to sound hitting the eardrum. The malleus is attached to the eardrum, and this is the first bone to receive vibrations. The incus is positioned between the malleus and the stapes, and it acts like a lever to transmit and amplify sound. Finally, the stapes is the last bone in our chain of ossicles, and it’s job is to push on the cochlea, (or the inner ear), fluid filled oval window to convert mechanical vibrations into electrical nerve signals.
When we experience fluid in our ears, such as when we have an ear infection, the middle ear space is the part of our ear that is most often involved. When this space fills with fluid, it can create a temporary type of hearing loss called a conductive hearing loss – the outer ear may be clear, and the inner ear beyond may be healthy and responding well, but fluid in the middle ear space can impact how efficiently sound is able to move through that space. Children are oftentimes more susceptible to middle ear related issues due to a variety of reasons. When we’re younger and smaller, our eustachian tubes are often smaller and more horizontal, but they grow and angle slightly downward as we age, allowing for improved equalization and more efficient function. Children are also still developing their immune systems, and may have higher exposure rates to colds and infections in daycare and school settings. This places children at an increased risk for illnesses that can sometimes lead to fluid buildup or infection in the middle ear space.
Finally, we have our inner ear. This part of our ear is responsible for hearing (the cochlea), and also houses our balance organ (the vestibular system). The sound vibrations that transmit from the middle ear vibrate the fluid that is housed within the cochlea, which then causes movement from tiny hair cells within the cochlea. When these hair cells move, they convert sound into electrical impulses, which are then sent to our brains to be processed. When the inner ear is exposed to loud noise, this can cause damage to our delicate hair cells. This type of damage is often permanent, and can result in hearing loss oftentimes referred to as sensorineural hearing loss. Our vestibular system is responsible for detecting movement, and helps us to maintain our balance and equilibrium.
While the ear has a seemingly simple job, there are a lot of moving parts (literally!) to ensure we are able to hear well. You can keep your ears healthy by having your doctor routinely check your outer ear for earwax, protect yourself from illness to the best of your ability to help keep your middle ear clear, and use hearing protection when you know you may be exposed to loud or harmful noise to protect your inner ear. Changes in hearing are oftentimes gradual, but if you or someone you know ever experiences a sudden or overnight change in hearing, especially if it’s accompanied by dizziness or vertigo, please call your doctor and get your hearing evaluated as soon as possible to determine which part of your ear has been affected.
