Conductive hearing loss is a type of hearing loss that occurs when sound is prevented from reaching the inner ear. This blockage is located either in the outer ear or the middle ear.
In this case, the inner ear is perfectly normal, but it sends no signal to the brain because sound does not reach it. Without impulses transmitted to the brain, the brain receives no sound information, resulting in hearing loss.
In conductive hearing loss, the sound level entering the ear is reduced on its way to the cochlea in the inner ear. This makes it difficult to hear soft sounds, while loud sounds seem muffled.
Causes of conductive hearing loss
Before discussing the symptoms of conductive hearing loss, let's examine some of its causes. Those we will review are located in the outer and middle ear.
1. Earwax impaction
Earwax impaction is also called cerumen impaction. It occurs when earwax builds up in the ear canal to the point of obstructing hearing.
Produced in normal quantities, earwax is beneficial for your ears. The body secretes it to prevent debris, liquids, and bacteria from reaching the inner ear. Accumulated earwax usually clears itself. When produced in excess, your ears may have difficulty getting rid of it.
When the ear can no longer clear earwax, it accumulates and often hardens. This plug then disrupts sound transmission in the ear.
There are two main causes of earwax impaction. The first: earwax is pushed deeper into the ear canal by objects like cotton swabs. The second: the presence of excess hardened earwax.
Generally, conductive hearing loss caused by earwax impaction lasts only as long as the impaction is present. You can have this impaction removed at home or by a medical professional.
Once the earwax impaction is removed, sound again travels easily from the outer ear to the inner ear, passing through the middle ear.
2. Fluid in the ear
Otitis media refers to a group of inflammatory diseases of the middle ear. It is often triggered by a buildup of fluid in the middle ear.
Acute otitis media is a common form. In addition to ear inflammation, it is accompanied by ear pain. Otitis media can cause conductive hearing loss in both adults and children.
Another form is serous otitis media with effusion. This involves the presence of non-infectious fluid in the ear for more than three months. It does not cause infection but can give an occasional sensation of a full ear.
3. Eustachian tube dysfunction
The Eustachian tube connects the middle ear to the upper part of the throat; it equalizes pressure in the ear and drains fluid from the middle ear.
The Eustachian tubes usually remain closed, but they open naturally when you yawn, chew, or swallow.
The Eustachian tube can become blocked for various reasons. This blockage causes tubal dysfunction, leading to pain, a feeling of fullness in the ear, tickling in the ear, tinnitus, and hearing difficulties.
Eustachian tube obstruction is often temporary and can be resolved with simple home remedies. However, it is important to consult a doctor for recurrent episodes.
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 membrane that separates the ear canal from the middle ear.
The eardrum plays an essential role in transmitting sound to the middle ear. If it is perforated, conductive hearing loss can occur. The location and size of the tear influence the degree of hearing loss.
Barotrauma can perforate the eardrum. Barotrauma corresponds to the stress exerted on the eardrum when the ambient air pressure and the middle ear pressure are no longer balanced.
A middle ear infection, a direct blow to the ear, exposure to intense noise, severe head trauma, or the presence of foreign bodies in the ear can also perforate the eardrum.
The good news is that a perforated eardrum often heals on its own within a few weeks. When this is not the case, the doctor may apply a patch or perform surgical repair. Once the tear is closed, hearing returns to normal.
5. Microtia
Microtia is a congenital malformation present in children. Although its exact cause remains unknown, it has been associated with drug or alcohol consumption, a low-carbohydrate diet, taking the acne medication Accutane, and certain genetic conditions during pregnancy.
This congenital malformation results in an underdeveloped or deformed outer ear in children.
Microtia often develops during the first trimester of pregnancy and primarily affects only one ear. In rare cases, it affects both ears.
Children with microtia often suffer from varying degrees of conductive hearing loss. Hearing loss can be partial or total and affect one or both ears. It can also be accompanied by a speech disorder.
6. Stenosis
Stenosis is the narrowing of the ear canal. It occurs when thick, hard fibrous tissue forms in places in the outer ear canal. The formation of this thick tissue causes conductive hearing loss.
Causes of stenosis include chronic or long-term otitis externa, chemical burns, gunshot wounds, and the accumulation of thick, dry skin in the ear canal.
Most stenoses are temporary and can be treated with ear drops.
7. Exostoses
Exostoses are also called bone growths. This is the formation of new bone or a bone-like protrusion on the surface of a bone. Exostoses can appear anywhere, including inside the ear.
It is also commonly referred to as "surfer's ear." This name comes from the fact that abnormal bone formation in the ear canal can result from exposure to cold wind and water.
Exposure of the ear to cold wind causes the bone surrounding the ear canal to develop small bony growths. This growth can narrow or obstruct the ear canal. The obstruction can then trap water and earwax in the ear and promote infection.
When these bony growths form in the ear canal, they create obstructions and limit the passage of sound from the outer ear to the inner ear.
Exostoses do not only affect surfers: they also affect people who engage in cold-weather activities, such as diving, kayaking, jet skiing, windsurfing, or sailing.
8. Tympanosclerosis
Tympanosclerosis is a condition that causes thickening or calcification of the tympanic membrane. There are no obvious symptoms associated with it, apart from conductive hearing loss.
Without proper medical examination, diagnosing tympanosclerosis can be difficult. The doctor must examine the ear to identify it: they look for whitish, chalky-looking patches on the eardrum.
9. Otospongiosis
Otospongiosis, or otosclerosis, is the medical term for the hardening or abnormal remodeling of the middle ear bones. Bone remodeling is a natural process in the body, designed to replace old tissues with new ones.
When this remodeling does not follow its natural course, it can disrupt the passage of sound from the middle ear to the inner ear and cause conductive hearing loss.
10. Ossicular chain discontinuity
Ossicular chain discontinuity refers to a break or interruption in the connection between the bones of the middle ear. The middle ear has three small bones: the incus (anvil), stapes (stirrup), and malleus (hammer). Together, they form what are called the ossicles.
Sound vibrations captured by the outer ear reach the eardrum, then propagate through the ossicles. The stapes then transmits these vibrations to the fluids of the inner ear.
If the ossicles are not properly connected or are separated, the middle ear no longer transmits sound to the inner ear. This results in conductive hearing loss.
Otospongiosis, infection, skull fracture, or trauma can cause ossicular chain discontinuity.
Symptoms of conductive hearing loss
The symptoms of conductive hearing loss often depend on the underlying cause of the hearing loss and can, in some cases, vary from person to person.
Since the cause of conductive hearing loss is located in the outer or middle ear, hearing difficulties generally relate to the volume of sounds.
This section reviews the early symptoms of conductive hearing loss, conductive hearing loss in one ear, and conductive hearing loss in children.
Early symptoms of conductive hearing loss
Here are some of the early symptoms of conductive hearing loss:
Difficulty hearing on the phone
Difficulty understanding what others are saying, especially in crowded places
Increasing the TV or radio volume beyond the usual level
Difficulty following conversations
Constantly needing to ask for repetition
Fatigue or stress related to the effort of concentrating to hear what others are saying
General symptoms of conductive hearing loss
The most common symptoms of conductive hearing loss, regardless of the cause, are:
Foul-smelling yellowish discharge or fluid leaking from the ear
Sensation that sounds are muffled
Sudden hearing loss in one or both ears
Difficulty understanding words in crowded places
Better hearing in one ear than the other
Sensation of full ears
Ear pain and headaches
Difficulty hearing soft sounds, whether low-pitched or high-pitched
Difficulty hearing consonants
Asking others to speak more slowly or loudly
Tendency to withdraw from conversations
Symptoms of conductive hearing loss in one ear
Conductive hearing loss can affect only one ear. It is often difficult to diagnose in such cases because hearing in the healthy ear is perfect.
Here are common symptoms of conductive hearing loss in one ear:
Poor hearing when sound comes from one side or a specific direction
Difficulty pinpointing the origin of a sound
Difficulty distinguishing different sounds
Inability to filter out background noise
Difficulty hearing from a distance and in noisy places
Symptoms of conductive hearing loss in children and infants
Newborn hearing is usually checked a few weeks after birth. However, it is still possible to miss hearing loss in a baby or child who shows no external abnormalities, such as those caused by microtia.
Moreover, gradually developing hearing loss can go unnoticed.
Symptoms of conductive hearing loss in infants and children include:
Reacting to your presence when they see you, but not when you call their name
Inability to say a recognizable word by fifteen months
Delayed speech and incomprehensible words
Speaking very loudly
Turning the TV volume up very high
Not startling at loud noises
Not turning towards your voice at four months
Not responding when you talk to them
Hearing some sounds but not others
Asking for repetition or giving irrelevant answers to questions
Symptoms of conductive hearing loss according to the cause
As mentioned previously, the symptoms of conductive hearing loss you experience can vary depending on the specific cause of the hearing loss.
For example, the symptoms of hearing loss due to a perforated eardrum differ from those related to Eustachian tube dysfunction.
Here are the most common symptoms associated with each of the causes of conductive hearing loss described above.
Symptoms of conductive hearing loss related to earwax impaction
Feeling of fullness in the affected ear
Intense ear pain
Reduced hearing in the affected ear
Tinnitus or ringing in the ear
Dizziness
Sudden or partial, and temporary, hearing loss
Discharge or bad odor from the affected ear
Symptoms of conductive hearing loss related to fluid in the ears
Ear pain that intensifies with altitude changes.
Sensation that sounds are muffled
Sensation of full or blocked ears
Tinnitus or ringing in the ears
Behavioral problems or decreased academic performance
Dizziness and loss of balance, in rare cases
Symptoms of conductive hearing loss related to Eustachian tube dysfunction
Feeling of full ears
Pain in one or both ears
Difficulty maintaining balance
Perception of muffled sounds
Tinnitus or ringing in the ear
Worsening of symptoms with altitude changes
Cracking or popping sensations in the ears
In children, complaints of tickling in the ears
Symptoms of conductive hearing loss related to a ruptured eardrum
Purulent, mucous, or bloody discharge from the ear
Ringing in the ear
Dizziness or sensation of spinning
Nausea or vomiting
Hearing loss in the affected ear
Ear pain that often disappears quickly
The difference between mild and moderate conductive hearing loss
Like all other forms of hearing loss, conductive hearing loss comes in several degrees of severity. In this article, we are interested in mild and moderate conductive hearing loss.
Hearing loss is categorized based on the minimum threshold a person can perceive. This threshold is measured in decibels (dB), the unit used to quantify sound intensity.
Before examining the difference between mild and moderate conductive hearing loss, it is important to remember that not all hearing losses are alike. Even with identical type and degree, the impact and experience differ from person to person.
Furthermore, classifying hearing loss as mild or moderate does not mean that the hearing and communication difficulties are also mild or moderate.
Mild conductive hearing loss
The threshold for mild hearing loss is between 25 and 40 decibels. Adults generally manage it well, but in children, mild hearing loss can hinder language development.
The sensation is similar to that of plugging one's ears with fingers. This hearing loss often results from an outer ear problem that prevents proper reception and transmission of sound to the middle and inner ear.
Moderate conductive hearing loss
Individuals with moderate conductive hearing loss have thresholds between 41 and 55 decibels. This hearing loss makes it difficult to perceive speech at a normal volume.
In most cases, doctors prescribe hearing aids for people with moderate hearing loss. In children, moderate conductive hearing loss often affects vocabulary, language, and comprehension.
Individuals with mild conductive hearing loss generally hear vowels but struggle to perceive soft consonants; those with moderate conductive hearing loss also miss consonants.
Furthermore, in most cases of mild conductive hearing loss, the hearing difficulty only concerns soft sounds. Moderate conductive hearing loss, however, also affects comprehension.
Without hearing aids, a person with moderate hearing loss hears speech but does not understand what you are saying. This symptom indicates that the cause extends beyond the outer ear and concerns the middle ear.
This means that the outer ear receives sound well, but the middle ear fails to transmit it to the inner ear, which sends the sound signal to the brain for interpretation. Individuals with moderate conductive hearing loss do not understand what you are saying, even though sound enters the ear. In cases of mild conductive hearing loss, sound may seem muffled, but comprehension is not impaired.
Most individuals with mild conductive hearing loss learn to manage it and lead normal lives, without consequences. Those suffering from moderate conductive hearing loss, however, often require hearing aids to function properly.
Treatments for conductive hearing loss
As previously mentioned, doctors can treat most cases of conductive hearing loss. Treatment can involve medication, surgery, or supportive care. The method chosen depends on the nature and location of the cause of the hearing loss.
There is no universal treatment for conductive hearing loss; management depends on the underlying cause. For example, treating conductive hearing loss due to earwax blockage is completely different from treating hearing loss related to a ruptured eardrum.
Treatment for conductive hearing loss caused by fluid in the ear
In most cases, fluid in the ear does not require treatment; it drains naturally within a few weeks. In some situations, your doctor will prescribe treatment, the nature of which depends on several factors.
If the fluid has been present for approximately six weeks, an audiogram will be performed, and antibiotics will likely be prescribed.
Antibiotics can also treat effusions present for twelve weeks. If an audiogram reveals significant hearing loss, the doctor may insert grommets into the ear to drain the fluid.
In severe cases, where fluid persists for four to six months, the doctor will need to surgically insert grommets, even in the absence of hearing loss.
In some cases, fluid in the ear is accompanied by an infection. In the absence of infection, antibiotics are useless. Certain medications like antihistamines can disrupt Eustachian tube drainage, and doctors do not recommend them.
However, if there is an ear infection, your doctor will prescribe the appropriate antibiotic.
Antibiotics your doctor may recommend include:
Amoxil (amoxicillin)
Ciprodex (ciprofloxacin/dexamethasone) suspension
Ocuflox (ofloxacin) solution
Augmentin (amoxicillin/potassium clavulanate)
Acetal HC (hydrocortisone/acetic acid) solution
Cortisporin (neomycin/polymyxin B/hydrocortisone) suspension or solution
Ciloxan (ciprofloxacin) solution
Ciprodex (ciprofloxacin/dexamethasone) suspension
Floxin (ofloxacin) solution
Cipro HC (ciprofloxacin/hydrocortisone) suspension
If the infection is accompanied by pain or fever, your doctor may prescribe pain relievers such as ibuprofen or paracetamol.
Children with fluid in the ear and developmental delay may require early treatment. Waiting for the fluid to resolve on its own can be detrimental. In the absence of developmental issues, waiting for spontaneous fluid drainage poses no risk.
Hearing usually returns to normal once the fluid is drained, either naturally or through surgery.
Treatment for conductive hearing loss caused by a ruptured eardrum
A ruptured or perforated eardrum often requires no treatment, as it heals spontaneously within a few weeks. If the tear does not close on its own, your doctor may resort to one of the solutions below.
1. Eardrum patch
This is a patch made of paper or another material, applied by an ENT specialist. Its purpose is to accelerate healing.
Before applying the patch, the ENT specialist applies a chemical to the edges of the tear. This product accelerates healing. Several patches may be necessary before the hole closes completely.
2. Surgery
Your doctor may suggest surgery if the patch has not allowed healing. In some cases, it is not necessary to try a patch before surgery; after examination, your doctor will be able to tell if a patch might suffice.
The procedure performed for a perforated eardrum is called tympanoplasty. It involves grafting a piece of your own tissue onto the eardrum to close the hole or tear.
The procedure is quite simple, and you can go home right after.
As previously mentioned, a ruptured eardrum can heal without any treatment.
However, there are ways to protect your eardrum and accelerate healing with home remedies and some habit changes, such as:
Avoid cleaning your ears with cotton swabs, hairpins, or other objects.
Avoid blowing your nose: the pressure exerted in the ear can reopen a healing tear.
Keeping your ears dry at all times prevents dirt or liquids from reaching the eardrum and infecting it. While showering, protect your ears with a cotton ball coated in petroleum jelly or a waterproof silicone earplug.
Avoid exposing your ears to loud noises.
If an infection accompanies the eardrum perforation, your doctor will prescribe an antibiotic. Treating the infection helps speed up healing.
Treatment for conductive hearing loss caused by Eustachian tube dysfunction
In cases of Eustachian tube dysfunction, working your jaw by yawning, swallowing, or chewing gum can relieve the sensation of full ears. You can also take a deep breath, pinch your nostrils, and blow with your mouth closed.
In infants, feeding or a pacifier promotes swallowing and relieves this sensation of fullness in the ear.
In some cases, these simple exercises are not enough to correct the dysfunction. It is then necessary to consult a doctor, who may propose the following solutions:
A corticosteroid nasal spray or an antihistamine can reduce the allergic reaction.
Your doctor may insert a small grommet into the eardrum to drain fluid accumulated in the middle ear. These grommets can stay in place for about eighteen months, then fall out naturally.
A decongestant can reduce swelling of the Eustachian tube lining. It constricts blood vessels and reduces edema.
During a myringotomy, the doctor makes a tiny incision in the eardrum and suctions fluid from the middle ear. The incision is left open to allow swelling to subside, which usually takes two to three days.
Balloon dilation
Your doctor inserts a small balloon through the nose into the Eustachian tube using a catheter. Once inflated, the balloon opens a passage allowing air and mucus to flow. The Eustachian tube then returns to its normal function.
Treatment for conductive hearing loss caused by earwax blockage
If your conductive hearing loss is due to an accumulation of earwax in the ear, do not try to remove the blockage yourself. You risk pushing it further into the ear canal and worsening the damage.
However, under medical supervision or with advice from a doctor, you may be able to remove the blockage at home. Here are some home remedies your doctor may recommend.
Softening earwax
You can soften earwax with over-the-counter drops designed for this purpose. Hydrogen peroxide, glycerin, paraffin oil, baby oil, or carbamide peroxide also work.
Once softened, the earwax flows out of the ear.
Ear irrigation
Ear irrigation is only recommended for people whose ear is not damaged. Irrigating an ear with a ruptured or perforated eardrum can cause infection or worsen hearing loss. It is also not recommended if you have recently undergone a medical procedure on the ear.
Over-the-counter ear irrigation products are available. For best results, follow these steps:
Sit or stand with your head straight
Grasp your earlobe and gently pull it
Using a syringe, inject a stream of body-temperature water into your ear
Tilt your head to let the water drain out
If you cannot remove the blockage yourself, your doctor can remove accumulated earwax by irrigation, suction, or with a curette.
Your hearing will return to normal once the earwax is removed.
Treatment for conductive hearing loss caused by microtia
As we have seen, microtia is a congenital anomaly or malformation of the external and internal ear. It is one of the causes of conductive hearing loss that may require surgery. Some parents choose not to treat it. Here are the possible therapeutic options:
1. Autologous ear reconstruction
This procedure involves taking cartilage from the child and reconstructing a new ear on the affected side. The child's tissues help the ear heal itself in case of injury.
This procedure is usually performed around the age of six. At this age, the child has enough cartilage. In addition, the healthy ear has reached its adult size, allowing the new ear to be the correct size.
Depending on the severity of microtia, autologous reconstruction requires three procedures, six months apart to allow the child time to heal.
During the first procedure, the surgeon takes the cartilage for the new ear. The second involves refining and repositioning the new lobe. Finally, during the third, the surgeon lifts the new ear to improve its alignment and makes the necessary finishing touches. If the child needs middle ear surgery, this occurs after the third operation.
Even if the new ear does not look exactly like the healthy ear, it will remain functional. It will also improve the child's appearance and allow them to wear prescription or sunglasses.
2. Surgically implanted hearing aids
Doctors can also treat conductive hearing loss related to microtia using a cochlear implant, placed in the bone above and behind the ear. Once the anchor point has healed, the doctor attaches a processor that helps the child hear by stimulating the nerves of the inner ear.
In addition to cochlear implants, doctors can use vibratory devices. Worn on the scalp, they are attached by magnets to surgically implanted devices. The implant is connected to the middle ear and transmits vibrations to the inner ear.
Even though surgically implanted devices require little healing time and do not create scar tissue, they do have adverse effects: tinnitus, dizziness, nerve damage, leakage of fluid surrounding the brain, skin infection, earwax accumulation, and worsening hearing loss.
3. External ear prosthesis or auricular epithesis
This is an artificial ear made of synthetic material, attached with adhesive or surgically implanted on the side of your child's head. Most of these prostheses are very realistic, and the procedure is less invasive than other therapeutic options.
The auricular epithesis is removable and perfectly suitable for children who cannot benefit from reconstruction. However, it needs to be replaced from time to time.
Another disadvantage: some children develop skin sensitivity to the adhesive used to attach the ear. The prosthesis also requires daily maintenance.
4. Medpor graft
This procedure resembles autologous ear reconstruction. But instead of using the child's rib cartilage, the surgeon implants a synthetic material. The child can be operated on from the age of three, and only one procedure is sufficient. A scalp flap covers the implant.
The lifespan of Medpor implants is unknown, so surgeons rarely recommend them. Moreover, since the implant is synthetic, it cannot integrate with the surrounding tissues: the child therefore risks losing it in case of shock or injury. The risk of infection is also high.
Treating conductive hearing loss with hearing aids
Hearing aids are battery-powered electronic devices designed to improve hearing. They are generally not prescribed for people with conductive hearing loss, as the cause is known: once treated, hearing returns to normal.
In some cases, however, treatment does not completely correct conductive hearing loss. The affected person may then benefit from a hearing aid. Similarly, if the organ of Corti in the cochlea is functioning correctly, a hearing aid can help transmit sound from the outer and middle ear to the inner ear.
Most hearing aids are small enough to be worn in or behind the ear; their basic function is to amplify sounds.
A hearing aid has three main components: a microphone that picks up environmental sounds, an amplifier that makes them louder, and a receiver that sends the amplified sounds into the ear.
Hearing aids are medical devices and must be fitted by an audiologist. After a thorough examination, they will determine the type of hearing aid you need and adjust it to your specific hearing needs. There is no universal hearing aid; all are personalized.
Hearing aids come in different styles and are worn in different places. Here are the most common styles.
In-the-canal (ITC) hearing aids
These hearing aids are placed inside the ear canal. Completely invisible-in-the-canal models fall into this category. Very small, they hide in the ear canal. Their small size makes them difficult to adjust or remove, and they are not suitable for children.
In-the-ear (ITE) hearing aids
These devices fit in the outer ear. They are suitable for people with mild to severe conductive hearing loss. ITEs are not suitable for children whose ears are still growing.
Behind-the-ear (BTE) hearing aids
These models are placed behind the ear. Sound is transmitted to the ear through a thin tube that enters the ear canal.
Receiver-in-canal (RIC or RITE) hearing aids
These hearing aids are worn behind the ear and are connected by a very thin wire to a receiver placed in the ear canal. With this type of device, low-frequency sounds naturally enter the ear while high-frequency sounds are amplified.
Conclusion
While some causes of conductive hearing loss are beyond your control, protect your ears as much as possible.
Avoid inserting objects such as hairpins or cotton swabs into your ear to remove earwax. You risk pushing it deeper into the ear canal and causing conductive hearing loss.
Also avoid exposing your ears to loud noises. Exposure to loud noise can damage both your eardrum and the organs of your inner ear.
Hearing aids can help you cope better with the symptoms of hearing loss.
If you experience hearing difficulties or any of the symptoms listed above, do not hesitate to talk to your doctor.
"The good news is that most patients with conductive hearing loss can be helped. Treatment can be life-changing. CLARIA hearing aids are an excellent solution when medication, surgery, or other devices are not feasible." – Drew Sutton, MD, Board-Certified ENT.
Sources:
About Conductive Hearing Loss | ASHA
Degrees of Hearing Loss | Hearing Health Foundation
Treatments for Eustachian Tube Dysfunction | Stanford Health Care
