Conductive hearing loss is a type of hearing loss that occurs when damage is done to the outer or middle ear. This damage to the outer or middle affects the transmission of sound to the inner ear.
The outer ear receives sound from the environment and transmits it to the middle ear through the ear canal. The sound is transmitted to the inner ear from the middle ear, where it is changed into electrical signals and transmitted to the brain for interpretation.
If either the outer ear or middle ear doesn't function properly, sound cannot be sent to the inner ear. Even though the inner ear is perfectly functioning, conductive hearing loss occurs because it does not receive any sound signals.
Conductive hearing loss can be caused by damage in the outer ear or in the middle ear. It is rare for both the outer ear and the middle ear to malfunction at the same time.
Middle ear conductive hearing loss is conductive hearing loss caused by a problem in the middle ear. The middle ear lies between the temporal bone and extends from the eardrum (tympanic membrane) to the inner ear’s lateral wall.
The middle ear’s major function is the transmission of vibration from the eardrum to the inner ear through the auditory ossicles. It also protects the inner ear through acoustic reflexes.
When the proper function of any of the middle ear structures is affected, the conduction of sound to the inner ear can be interrupted. This interruption in the conduction of sound is what is referred to as middle ear conductive hearing loss.
Middle Ear Conductive Hearing Loss Symptoms
The symptoms of middle ear conductive hearing loss can vary depending on the root cause. However, there are some general symptoms observed in people with this type of hearing loss.
Common symptoms associated with middle ear conductive hearing loss include the following.
- Sudden or unexpected hearing loss in one or both ears.
- Loss of balance or dizziness.
- Severe or mild ear pain.
- Drainage of fluid, blood, or puss-like substance from the affected ear.
- A feeling that sounds are muffled or blocked in the affected ear.
- A feeling of stuffiness or fullness in the affected ear.
- Difficulty hearing both low-pitched and high-pitched sounds.
Middle Ear Conductive Hearing Loss Causes
As already stated, middle ear conductive hearing loss is caused by the malfunctioning or damage done to the middle ear structures. Let's examine some of these damages that can cause middle ear conductive hearing loss.
1. Fluid in the Ear
This is also known as otitis media with effusion. It is the accumulation of fluid behind the eardrum caused by damage to the eustachian tube.
The eustachian tube is responsible for draining fluid from the ear into the back of the throat. When this tube becomes clogged, fluid gets trapped in the middle ear. The trapped fluid is called an effusion.
Respiratory infections, allergies, and irritants such as cigarette smoke can cause the lining of the eustachian tube to swell and result in the build-up of fluid.
Also, sudden changes in air pressure and drinking while lying on your back can block the eustachian tube.
Fluid in the ear is more common in children under age two because their eustachian tube is shorter, straighter, and more horizontal than that of adults. This makes it easy for bacteria to enter.
In most cases, there is no need for treatment for fluid in the ear. The fluid drains out naturally within a few weeks.
Barotrauma is the injuries caused by an increase in air or water pressure experienced during airplane flights or scuba diving. Barotrauma affects the entire body, including the ears.
Ear barotrauma occurs when the eustachian tube is blocked due to a change in pressure. The pressure changes create a vacuum in the middle ear, which causes the eardrum to be pulled inward. This results in ear pain and middle ear conductive hearing loss.
In severe cases, in a bid to equalize the pressure on both sides of the eardrum, the body fills the middle ear with clear fluid. This fluid is gotten from the blood vessels in the inner ear’s lining and will drain out when the eustachian tube is open.
If the pressure on the eardrum is too much, it can rupture. The pressure can also create a leak known as fistula between the cochlea and the semicircular canals. This fistula can cause loss of balance or vertigo.
Symptoms of barotrauma include: ear pain, feeling of fullness in the ear, bleeding or fluid from the ear, dizziness, and conductive hearing loss.
Barotrauma can be treated by yawning, chewing, or swallowing regularly during flights, the use of decongestants, and in some cases, surgery.
This is an abnormal noncancerous skin growth that grows in the middle section of the ear behind the eardrum. Repeated muddled ear infections often cause it.
A cholesteatoma starts off as a cyst that sheds layers off old skin. After a while, these dead skin cells begin to accumulate and increase in size. As the growth increases in size, it presses against and destroys the middle ear’s delicate bones.
A cholesteatoma can also be caused by a poor functioning eustachian tube. If the eustachian tube is not functioning properly due to a sinus infection, allergies, cold, and chronic ear infections, a vacuum may be created in the middle ear.
The eardrum can be pulled into this vacuum and create a cyst which can turn into a cholesteatoma.
Symptoms of cholesteatoma include the draining of a foul-smelling fluid from the ear, aching pain in or behind the ear, and conductive hearing loss.
4. Eardrum Ruptured
An eardrum rupture is a small tear or hole in the eardrum. The eardrum divides the middle ear and the outer ear canal. It vibrates when a sound wave enters the ear, this vibration is vital for hearing.
When the eardrum is ruptured or perforated, it can no longer vibrate when the sound gets into the ear. This results in conductive hearing loss.
An eardrum rupture can be caused by ear infections which result in the accumulation of fluid behind the eardrum, pressure changes, direct, forceful impact to the ear, head injuries, inserting objects into the ear and sudden or constant exposure to loud noise.
Symptoms of eardrum rupture include severe pain, puss-filled, watery or bloody discharge from the ear, tinnitus, dizziness, and conductive hearing loss.
A ruptured eardrum can get healed after a few weeks without any treatment. If, however, the year doesn't seal up. Naturally, an eardrum patch or other surgical treatments can be used to seal up the tear.
Tympanosclerosis refers to the scarring of the eardrum which occurs after surgery or an injury. The scarring on the eardrum is usually seen as a bright white lesion on or under the eardrum.
Tympanosclerosis can affect only the eardrum (myringosclerosis), or it can affect other middle ear structures like the mastoid cavity or ossicular chain (Intratympanic Tympanosclerosis)
Even though the exact cause of Tympanosclerosis is unknown, it has been linked with acute and chronic otitis media and atherosclerosis. Children who have had a ventilation tube inserted into their ear for otitis media with effusion are susceptible to Tympanosclerosis.
Aside from the white lesions’ presence on the eardrum and conductive hearing loss, tympanosclerosis has no other associated symptoms.
6. Other Causes
Other factors that can result in middle ear conductive hearing loss include; eustachian tube blockage, congenital malformation of the ossicles, ossicular discontinuity caused by infection or temporal trauma, and otosclerosis.
Middle Ear Conductive Hearing Loss Treatments
Middle ear conductive hearing loss is often temporary, but there is no general treatment for all the causes.
Middle ear conductive hearing loss is treated by identifying the underlying cause and treating it.
If a tear causes hearing loss in the eardrum, the hearing will return to normal when the tear heals. The same is true for all the other causes.
Once the root cause is identified, and the appropriate treatment for the condition is administered, the hearing loss will disappear.
In some cases, no treatment or medical treatment is required. The problem is resolved naturally. An example of such instances is when the build-up of fluid causes hearing loss in the ear.
Middle ear conductive hearing loss can be discomforting, but your hearing should return to normal within a short time with the right medical attention.
If you suspect you have a middle ear conductive hearing loss, ensure you inform your doctor before you start any treatment. This will enable you to be certain of the exact cause and the appropriate way to treat it.
Do you have middle ear conductive hearing loss? What caused the hearing loss?
We would love to hear from you.