The middle ear, a very important part of the hearing system! Its main function is to transfer acoustic energy from the air-filled outer ear into mechanical energy in the fluid-filled inner ear. The main component of the middle ear are the ossicles, which are three tiny bones that fit and work together to transfer energy. Another important part of the middle ear system is the eustachian tube (ET). The ET is responsible for ventilation and drainage as it is connected to both the middle ear and the nasopharynx. It helps maintain a normal pressure in the middle ear as well as gets rid of any foreign debris or fluid. It is integral to normal middle ear function and many issues that affect the middle ear are caused by eustachian tube dysfunction.
The most common middle ear dysfunction is otitis media, or an ear infection. It is what we think of when we think of having an ear infection and happens when the middle ear becomes filled with fluid. When this fluid is unable to drain through normal eustachian tube function, it becomes the perfect place for viruses and bacteria to thrive. Symptoms are typically an earache, sometimes with pus or liquid coming out of the ear, an inflamed eardrum, outer ear sensitivity, and sometimes a slight conductive hearing loss. Luckily, otitis media is easily treated with antibiotics and often will go away on its own over time, restoring normal middle ear function and hearing. Sometimes you can get fluid without having an infection.
Children are more prone to chronic otitis media as the eustachian tube is straighter than in an adult which makes drainage more difficult. Sometimes children with chronic otitis media go through a myringotomy surgery that places tubes in the eardrum to allow proper drainage. So the fluid is still there, maybe just no infection. Eventually and usually, these tubes will fall out on their own and sometimes they will leave a small hole in the eardrum which could also heal on its own over time. This will likely, but not always leave scarring that may be or not apparent during an otoscopy exam but does not cause long term hearing issues. This scaring is called tympanosclerosis. If chronic otitis media is not treated it can result in tympanosclerosis. This also appears as scarring on the eardrum in white marks or streaks. These cause the eardrum to stiffen and can result in a low frequency hearing loss.
Barotrauma – Pressure Changes:
Another disorder that may arise from eustachian tube dysfunction is barotrauma (like snorkeling or flying) which is caused by extreme pressure changes. It usually feels like a build-up of pressure in your ears, like when your ears become plugged when flying in a plane or diving deep underwater. Chewing gum, yawning, or plugging your nose and trying to push air out of your ears usually solves this problem and your middle ear pressure is restored to normal. If your eustachian tube is unable to restore equilibrium to your middle ear and barotrauma persists it can be accompanied by ear pain, dizziness, a slight hearing loss, and can occasionally cause the eardrum to rupture. Barotrauma almost always solves itself but occasionally doctor intervention and surgery to the eardrum are needed.
An Chronic open eustachian tube:
A patulous (open) eustachian tube is another disorder that affects the middle ear, but luckily does not have any effects on someone’s health. The cause of patulous eustachian tube is unknown but it happens when the eustachian tube remains in an open position. Because the eustachian tube is usually closed, only opening when swallowing, yawning, chewing, etc. a constantly open ET is usually a great annoyance to those who experience it. When someone has a patulous eustachian tube it causes them to hear their own voice and breathing, have a feeling of fullness in their ears, and often to have an aversion to abnormal or loud sounds. It does not usually have an effect on hearing besides being annoying, but it is important to note if someone that needs a hearing aid has a patulous eustachian tube as it can especially aggravate the annoyance of always hearing their own voice and breathing. Although there are no negative health side effects, patulous eustachian tube can deeply affect someone’s quality of life. Treatments can include nasal sprays, putting one’s head in between their knees, and in serious cases, surgery.
The Middle Ear bones:
The ossicular chain, Malleus, Incus, Stapes, can also be affected by different disorders that usually result in hearing loss. Otosclerosis causes a spongy growth to form on the stapes (the smallest bone in the ossicular chain), which inhibits the bone from vibrating freely, causing hearing loss. Although there is no known cause for otosclerosis, it is believed to be a genetic condition that typically affects white women over 35 and becomes especially apparent after pregnancy. A low frequency hearing loss that can worsen over time is the most common symptom, but it can also be accompanied by tinnitus and sometimes vertigo. It can be treated with surgery which is quite invasive as it involves bypassing the stapes with a prosthetic bone in its place. Because the surgery is so invasive, many people chose to wear hearing aids to help with the hearing loss instead. Obviously hearing aids cannot solve the problem but they are a great tool!
At Hears to U, Audiology we love to find the right hearing aid for you and Kim, our audiologist, even wears a hearing aid because of otosclerosis in her right ear. More on that in another blog.
Other affects of ossicular chain issues:
Head trauma and aging can also affect the ossicular chain and cause hearing loss. Severe head trauma and middle ear aging can cause the ossicular chain to become loose. The opposite can also happen when the ossicles become fused and affect their mobility. Both disorders affect the ability for the ossicular chain to properly transfer sound energy which results in a conductive hearing loss. Hearing aids are once again a great tool to help these kinds of hearing loss. Although an ENT is needed to diagnose these issues, once you have a diagnosis, we can help you find the perfect hearing aid for your needs.
One of the most severe disorders that can affect the middle ear is cholesteatoma. Cholesteatoma is typically a result of ET dysfunction as old skin cells become trapped in the middle ear and they start to form an irregular growth. This growth, when not addressed, leads to chronic infection and can even perforate the eardrum if it becomes big enough. Typically, those with cholesteatoma experience frequent drainage with a strong-smelling discharge accompanied by a slight hearing loss. Oral and topical antibiotics may be prescribed to help fight infection but surgery is needed to completely get rid of the growth. If surgery is successful there still may be hearing loss. Once the ear is dry and infection-free hearing aids can be a great tool to help.