Have you ever wondered what your eardrums look like? A healthy eardrum is usually transparent. It looks not unlike a piece of clear plastic stretched out into a nearly round shape. Your eardrum doesn’t grow as you age. A newborn’s eardrum is the same size as the eardrum of an adult. Your eardrum is attached to a tiny bone known as the malleus. Because your eardrum is transparent, it is possible for your ENT or your audiologist to see through it into the middle ear space and another bone known as the incus.
But your eardrum isn’t all your ENT, or your audiologist can see in your ear with a device called an otoscope.
The Human Ear is an amazingly Complex Organ
The human ear is a complex organ far beyond the reach of even modern bioengineering. It is a collection of unique, tiny bones, nerves, and tissues that can translate sound waves first into mechanical motion and then into electrical signals that are sent to your auditory brainstem to be interpreted.
Because your eardrum is so thin, your audiologist can use an otoscope to visualize many of the structures of the middle ear. These include the bones of the middle ear and the space known as the tympanic cavity behind your eardrum. But the eardrum is the point of reference that your audiologist looks for to make sure all the other structures are normal.
What’s involved in being able to See your Eardrum?
Your eardrum is about 0.6 of an inch (1.5 cm) inside your skull at the end of the external ear canal. The external ear canal isn’t straight. This is a good thing, because it would be much easier to damage it with objects going into your ear if there weren’t a sharp bend in the canal.
Your audiologist won’t be able to visualize your eardrum with a traditional optical otoscope if your external auditory canal is filled with earwax. Removing ear wax is a safe and simple procedure in your audiologist’s office, but one should leave to the professionals. Probing your ear with a flexible object like a Q-tip can easily damage your eardrum. But even if the earwax is hard, your audiologist can use a digital otoscope to navigate around it to get a good view of your eardrum.
Once your audiologist has a clear line of sight into your middle ear, what can be seen?
The first thing your audiologist sees is a large circular area, which is the tympanic membrane, also known as the eardrum. With the lighting available from an otoscope, it may appear pearly gray. It will be about 0.4 inches (1 cm) in diameter.
Healthy eardrums are concave, that is, they curve inwards. They reflect a cone of light from the middle of the eardrum to the edges.
The next landmark your audiologist will look for is the malleus bone. This is the structure that transmits the vibrations of the eardrum to the inner ear through a network of bones starting with the malleus and moving to the incus and stapes. These bones are commonly called hammer, anvil, and stirrup, after their shapes.
The malleus is surrounded by a network of tiny blood vessels. The ease with which your audiologist can see these blood vessels is a good indicator of the health of your ear. And while your audiologist will always know whether they are looking into your left ear or your right ear, they can tell whether photographs taken with an otoscope of your middle are the left ear or the right ear by the position of the malleus. The malleus always points toward your face.
Strictly speaking, the “eardrum” isn’t the entirety of the tympanic membrane. The larger, tighter portion of the tympanic membrane that gets the most attention is the pars tensa. It’s the larger part of the membrane that is under greater tension, a little like stretching plastic wrap on top of a bowl. This is the part of the tympanic membrane that vibrates when sound waves come in through your ear canal.
Your eardrum also has a smaller, looser section known as the pars flaccida. It is thicker than the pars tensa. Because this part of the membrane isn’t stretched tight, it doesn’t play an active role in transmitting sound. But it provides complete coverage of the middle ear space and anchors the larger pars tensa.
The larger part of the eardrum, the pars tensa, is where problems are most likely to be seen. This is where your hearing specialist will see perforations from a ruptured eardrum, oozing effusions from infection, or convex, outward swelling from middle ear infections (otitis media).
However, the pars flaccida is the first part of the eardrum to bulge out if you have an infection or obstruction affecting your Eustachian tubes. Your Eustachian tube keeps pressure on both sides of your eardrums the same, so your ears respond accurately to the changes in air pressure that make sound.
Visualizing your eardrum is just part of your hearing exam at a professional audiologist clinic, like Harbor Audiology and Hearing Services. The hearing specialists at Harbor Audiology can provide you with the hearing care you need to achieve the best hearing possible. They can even help you choose the best of the most advanced hearing aids available today.