Conductive hearing loss is a type of hearing loss that occurs when sound is unable to pass through the outer and middle ear to the inner ear. Even though the major organs responsible for processing and sending sound signals to the brain are located in the inner ear, they won’t have any signal to transmit if the sound is unable to get to them.
Every sound you hear passes through various steps where the sound waves are changed into electrical signals. When sound waves in the air get into the outer ear, they travel through the ear canal and get to the eardrum.
When the eardrum receives the sound waves, it begins to vibrate. These vibrations are sent to these tiny bones (malleus, incus, and stapes) located in the middle ear.
These tiny bones amplify the sound of the vibrations and then send them to an organ in the inner ear known as the cochlea. The cochlea is filled with fluid. This fluid begins to ripple when the vibration gets to it. This rippling causes a traveling wave to form along the basilar membrane.
The basilar membrane is an elastic partition that splits the cochlea into the upper and lower part. It is the base on which the cochlea sits.
When the wave is formed on the basilar membrane, the hair cells in the inner ear detect the vibration and begin to move up and down.
As the hair cells move up and down, their projections, known as stereocilia, bump against the overlying structure and bend. When the bend, the stereocilia open up, a chemical rushes into the cells; this creates an electric signal.
The auditory nerve carries this electric signal to the brain. The brain then interprets the electric signals into recognizable and understandable sounds.
Having understood the detailed process of how hearing occurs, you must have already discovered the key role played by the outer and middle ear. If the inner ear is perfectly functional, but no sounds are coming in from the outer and middle ear, the inner ear cannot generate any electrical signals.
Conductive hearing loss often occurs as a result of damage to either the outer ear or middle ear. Damage to both the outer and the middle ear at the same time is often rare.
In some cases, sound may be able to get into your ear, but the sound level is reduced on its way to the inner ear. This makes it hard to hear soft sounds, and loud sounds also become muffled.
Causes of Conductive Hearing Loss
Before we proceed to look at the symptoms of conductive hearing loss, let's examine some of its causes. The causes we will be examining in this section will be both outer ear and middle ear causes.
1. Earwax Blockage
Earwax blockage is also known as Cerumen Impaction. It occurs when there is an accumulation of earwax in the ear canal which makes hearing difficult.
Earwax produced at the normal level is good for your ears. The wax is produced by the body to prevent debris, fluids, and bacteria from getting into the inner ear. The built-up wax normally works its way out of the ear naturally. But when it is produced in excess, your ears may have a hard time getting rid of it.
When the ear is unable to get rid of the wax, it begins to accumulate, and in most cases, it solidifies. This blockage affects the flow of sound that is being transmitted into the ear.
Two major reasons cause earwax blockage. The first is when earwax is pushed further into the ear canal by the use of objects like cotton buds. The second cause of earwax blockage is the presence of solid excess wax.
Usually, conductive hearing loss caused by earwax blockage only lasts for as long as the blockage exists. The earwax blockage can be removed at home or in the hospital.
When the ear wax which creates a blockage in the ear canal is removed, sound can easily travel from the outer ear through the middle ear into the inner ear.
2. Fluid in the Ear
Fluid in the ear is also known as Otitis Media with Effusion(OME), Middle Ear Effusion (MEE), or Serous Otitis Media (SOM). This is an accumulation of fluid behind the eardrum in the middle ear that can occur under any condition in which the auditory tube is impaired.
The fluid that collects in the middle ear is known as serous. It is usually a yellowish or straw-colored mucus or liquid. Serous accumulates in the middle ear when the auditory tube and the eustachian tube responsible for draining the fluid out of the ear do not function properly.
Fluid in the ear can be caused by ear infections, colds, and allergies that cause the auditory tube’s inflammation.
Children are more susceptible to fluid in the ear than adults. This is because the eustachian tube in children is leveler and shorter. This makes it hard for fluid to drain out of the middle ear. The eustachian tube of adults is longer and has a more sloped angle; this allows gravity to drain the fluid.
Otitis media often occurs in children between three to seven years of age. It usually gets resolved in a month, but in cases where it is unresolved, a pediatrician can remove the fluid.
3. Eustachian Tube Dysfunction
The eustachian tube is a small passageway that connects the middle ear to the throat. The eustachian tube is responsible for draining fluid from the middle ear and equalizing ear pressure.
It is always closed to prevent fluid and air pressure from building up inside the ear. It only opens when you swallow, yawn, chew or sneeze.
The eustachian tube can get clogged for a variety of reasons; this condition is called eustachian tube dysfunction.
When the eustachian tube gets clogged, you begin to experience a feeling of fullness in your ear, and sounds become muffled.
The feeling of fullness and pain that accompanies eustachian tube dysfunction can cause hearing difficulties and hearing loss.
Eustachian tube dysfunction can be caused by allergies such as cold and sinus, inflating, and clogs the eustachian tube with mucus. The dysfunction can also be caused by altitude changes experienced during hiking, elevator rides, mountain travel, and flying on planes.
Depending on the cause, eustachian tube dysfunction can disappear on its own without any medical intervention. Basic home treatments can also handle it. In cases where it is severe, you will have to see an ENT doctor.
4. Perforated Eardrum
A perforated eardrum, also known as a ruptured eardrum or tympanic membrane perforation, is a tear or hole in the eardrum. The eardrum is a thin tissue that separates the ear canal from the middle ear.
The eardrum plays a vital part in the transmission of sound to the middle ear. If it is perforated, conductive hearing loss may occur. The location and size of the tear can affect the degree of conductive hearing loss.
Eardrum perforation can be caused by barotrauma. Barotrauma is the stress put on the eardrum when the air pressure in the environment and air pressure in the middle ear is out of balance.
A perforated eardrum can also be caused by a middle ear infection, direct blow to the ear, exposure to loud noise, severe head trauma, and foreign objects in the ear.
The good news is that perforated eardrum often heals without treatment within a few weeks. In cases when it doesn't heal, a patch or surgical repair can be conducted. Once the tear has healed, hearing returns to normal.
Microtia is a congenital abnormality that is characterized by the underdevelopment and malformation of the external part of a child's ear.
Microtia often occurs during the first trimester of pregnancy. Even though the exact cause is unknown, it has been linked to the use of drugs or alcohol during pregnancy, a diet low in folic acid and carbohydrate, diabetes, and an acne medication known as Accutane.
The grade, severity, or level of microtia varies.
Below are the grades and their presentations:
Grade IEven though the external ear is present and normal, it appears small. The ear canal, on the other hand, is narrowed or missing.
Grade IIThe top two-thirds of the external ear is small and malformed, while the bottom third of the ear, including the earlobe, is normal. The ear canal is also either missing or narrowed.
Grade IIIThe ear canal is absent and underdeveloped; small parts of the external ear are present. This includes a small amount of cartilage at the top and the beginnings of a lobe.
Grade IVThis is also referred to as anotia. It is characterized by the absence of an ear or an ear canal. This is the most severe form of Microtia.
Children with microtia often suffer varying degrees of conductive hearing loss. The hearing loss can be partial or total, and it can affect one or both ears. A speech impediment can also accompany this hearing loss.
Conductive Hearing Loss Symptoms
The symptoms of conductive hearing loss often depend on the root cause of the hearing loss and in some cases the symptoms may vary.
Because the cause of conductive hearing loss is in the outer or middle ear, the hearing difficulties that occur are usually related to the loudness of the sound.
This section will examine the early symptoms of conductive hearing loss, symptoms of conductive hearing loss in one ear, and symptoms of conductive hearing loss in children.
We will also be looking at specific conductive hearing loss symptoms associated with the different causes of conductive hearing loss we examined above.
Early Symptoms of Conductive Hearing Loss
Here are some of the early symptoms lg conductive hearing loss:
- Difficulty hearing on the phone.
- Difficulty hearing and misunderstanding what other people are saying, especially in crowded places.
- Increasing the volume of television or radio above the normal volume range.
- Difficulty keeping up with conversations.
- Constantly asking for repetition.
- Fatigue or stress. This is associated with having to concentrate on hearing what is being said.
General Symptoms of Conductive Hearing Loss
The common conductive hearing loss symptoms you will experience irrespective of the cause include the following:
- Foul-smelling, yellow fluid, or discharge from the ear.
- Perception of muffled sound in the ear.
- Sudden hearing loss in one or both ears.
- Difficulty understanding words in crowded places.
- Ease hearing with one ear than the other.
- Feeling of fullness in the ears.
- Earache and headache.
- Difficulty hearing both low-pitched and high-pitched soft sounds.
- Difficulty hearing consonants.
- Asking others to speak slowly or loudly and withdraw from conversations.
Symptoms of Conductive Hearing Loss in One Ear
Conductive hearing loss can occur in one ear. This type of conductive hearing loss is often hard to diagnose because hearing in the unaffected ear is perfect.
A common cause of conductive hearing loss in one ear is an earwax blockage.
Below are common symptoms of conductive hearing loss in one ear:
- Poor hearing when the sound is coming from one side or direction.
- Difficulty when trying to tell where sound is coming from.
- Difficulty differentiating different sounds.
- Inability to ignore background noise.
- Difficulty hearing over long distances and in noisy places.
Symptoms of Conductive Hearing Loss in Children and Babies
Babies often have their hearing checked a few weeks after birth. But it is possible to miss the presence of a hearing loss in babies and children if it is not characterized by external abnormalities like those caused by microtia.
Also, if the hearing loss happens gradually, it may be hard to notice.
Symptoms of conductive hearing loss in babies and children include;
- Noticing you when they see you but not when you call their names.
- Inability to say any recognizable word at fifteen months.
- Slow to talk and speaking incoherent words.
- Talking very loudly.
- Turning up the volume of the television very high.
- Not getting startled by loud noises.
- Not turning toward your voice at four months.
- They don't reply when you talk to them.
- They can hear some sounds but not others.
- Ask for repetition or respond inappropriately to questions.
Symptoms of Conductive Hearing Loss Caused by Specific Problems
As stated earlier, the symptoms of conductive hearing loss you experience may vary based on the hearing loss’s specific cause.
For instance, the symptoms you may experience if a perforated eardrum causes the hearing loss will vary from hearing loss symptoms caused by eustachian tube dysfunction.
Below are the common symptoms associated with specific causes of conductive hearing loss explained above.
Earwax Blockage Related Conductive Hearing Loss Symptoms
- Feeling of fullness in the affected ear.
- Severe earache
- Decreased hearing in the affected ear.
- Tinnitus or noise in the ear
- Temporary, sudden or partial hearing loss.
- Drainage of fluid or odor from the affected ear.
- Unremoved earwax can also cause ear infections.
Symptoms of Conductive Hearing Loss Caused by Fluid in the Ears
- Ear pain. The ear pain becomes severe when there is a change in altitude.
- The sensation that sounds are muffled.
- Feeling that the ear is plugged or feeling of fullness in the ear.
- Tinnitus or ringing in the ears.
- Behavior problems and poor performance in school.
- In rare cases, vertigo and loss of balance may be experienced.
Eustachian Tube Dysfunction Related Conductive Hearing Loss Symptoms
- Feeling of fullness in the ears.
- Pain in one or both ears.
- Difficulty maintaining balance.
- Sounds being heard sound muffled.
- Tinnitus or noise in the ear.
- Worsening of symptoms when there is a change in altitude.
- Popping or clicking sensation in the ears.
- Children may complain of their ears tickling.
Symptoms of Conductive Hearing Loss Caused by the Eardrum Rupture
- Pus-like, mucus-like, or bloody drainage from the ear.
- Ringing in the ear.
- Vertigo to spinning sensation.
- Nausea or vomiting.
- Loss of hearing in the affected ear.
- Ear pain. This ear pain often subsides quickly.
While some conductive hearing loss causes may be out of your control, endeavor to protect your ears as much as you can.
Avoid inserting objects like bobby pins or cotton buds into your ear when trying to get rid of earwax. This can push the wax deeper into your ear canal and cause conductive hearing loss.
Also, ensure that you avoid exposing your ears to loud noise. Exposure to loud noise can damage both your eardrum and the organs in your inner ear.
If you notice any hearing difficulties or any of the symptoms listed above, don't hesitate to tell your doctor.
Have you suffered a conductive hearing loss? What caused it, and what were the symptoms you experienced. Share your experience with us.