Conductive hearing loss is caused when there is an obstruction or disruption to the flow of sound through the outer and or middle ear. I have commonly described this to students or patients as a “roadblock” in the ear that makes it difficult for sound to proceed on the “road” ahead. But, much like most “roadblocks”, conductive hearing loss does not make it impossible or impassable! Depending on the nature of the blockage, it might be a simple “drive” around the obstruction…. Or you might need to get out and move/ remove it, or it might just take a bit more “acceleration” to go through or over the obstruction.
For this reason, conductive hearing loss does not typically result in “deafness” but rather hearing loss that can range from mild to severe depending on the nature of the obstruction/”roadblock”!
Causes of Conductive Hearing Loss
Conductive hearing loss occurs when there is an obstruction or an interference with sound traveling through the outer or middle ear. There are a myriad of causes for such a hindrance including the following:
- Cerumen or wax build up (Cerumen is a natural occurrence in the ear and only becomes problematic if it occludes the ear canal. If this occurs, it is best if you seek professional removal from you PCP, if they are properly equipped and trained, an ENT (Ear Nose Throat specialist), or your Audiologist
- Foreign body in the ear
- Anomaly of the outer ear that is most often found at birth known as microtia or anotia which is frequently accompanied by narrowing or closure of the ear canal called “stenosis” or “atresia”
- Bony growths in the ear canal. These growths are benign and also known as “exostoses”. This most commonly occurs with prolonged exposure to cold water or wind but has been known to be spontaneous and/or hereditary.
Middle Ear:
- Perforation of the tympanic membrane also known as the eardrum.
- Collapse of the tympanic membrane
- Cholesteatoma is a growth that occurs in the middle ear that is benign and frequently made of wax and dead skin cells but can grow causing significant destruction in the middle ear. If left untreated, it can become large enough to erode into the cranial cavity which could then be considered life threatening.
- Fluid which can become infected causing what we commonly refer to as an “ear infection” or “otitis media”. This is typically a result of eustachian tube dysfunction that causes pressure to build up in the middle ear cavity and then fluid to accumulate and not properly drain.
- Disarticulation or disruption to the bones in the middle ear which due to their shape, are commonly referred to as the “hammer, anvil, and stirrup”. Medically they are the “ossicles”, “Malleus, Incus, and Stapes”. This disarticulation can be caused by trauma, growths in the ear such as a cholesteatoma, or infection left to cause erosion.
- Abnormal hardening of the middle ear bones known as “otosclerosis”
What Are the Symptoms of Conductive Hearing Loss?
Conductive hearing loss is typically characterized by the following symptoms that can happen in isolation or together:
- Decreased hearing or hearing that seems “muffled”
- A feeling of fullness or a “plugged” sensation
- Pressure in your ear
- Possible pain which is localized in the ear is professionally referred to as “otalgia”.
Conductive hearing loss can also present with other less common symptoms such as dizziness, drainage from the ear, and/or tinnitus.
Conductive hearing loss can occur suddenly or come on gradually.
In children that cannot recognize and verbalize what they are feeling, they might show the following signs/symptoms:
- Pulling at their ears.
- Irritability
- General signs of hearing loss which can be unresponsiveness to sound stimulus, turning or “cocking” their head to hear, asking for repetition (if they are verbal), talking loud, or reducing vocalizations.
- Fever (if caused by infection)
Difference Between Conductive Deafness and Sensorineural Deafness
Conductive hearing loss differs from sensorineural hearing loss because of where the loss is originating. Conductive losses stem from disruption in the outer and/or middle ear. Sensorineural hearing loss stems from loss further along the pathway from the inner ear on up the auditory pathway to the brain.
Conductive hearing loss can frequently be helped by medical intervention such as a procedure to remove or repair the blockage/ disruption, or medication. Sensorineural hearing loss is most often treated with amplification in the form of hearing aids or an implant.
How is Conductive Deafness Diagnosed?
Conductive hearing loss is diagnosed by first taking a thorough case history including the individual’s current symptoms, as well as their general health history.
Otoscopy is used to determine if there is a blockage of wax or a foreign body. If there is, questions will be asked to determine if it can be safely removed in the office, in some cases, once the occlusion is removed, there is immediate relief.
Tympanometry is used to ascertain 3 main things:
- Is the ear canal a normal volume? If the volume is smaller than it should be, there may still be blockage. If it is larger than normal it may indicate a perforation in the eardrum.
- Is the eardrum moving as it should? If the eardrum is not able to move as it should, this most commonly denotes the possible presence of fluid behind the eardrum though there are other reasons such as scarring or the presence of a mass. Sometimes the eardrum is what we call “hypermobile” or moving more than expected suggesting a flaccid tympanic membrane; this can also occur with disarticulation of the ossicles (aka: middle ear bones that are broken or not connected as they should be.)
- Is the air pressure level behind the eardrum within expected limits? Most commonly an abnormality would be negative pressure which can suggest that the eustachian tube is not functioning as it should to equalize pressure.
Pure Tone audiometry gives much useful information including if there is hearing loss present and if so, to what degree and what type of hearing loss it is. We first present these tones with air conduction through earphones determining how loud the individual needs the sound in order to hear it. We then place a device on the head called a bone conducer and use vibration to deliver the sound. This is a way to go more directly to the cochlea and auditory nerve bypassing any possible obstruction or anomaly in the outer or middle ear. (This is the detour around the roadblock so to speak if we refer to our original analogy). If the individual can hear better with the bone conduction we know that there is a conductive component to their hearing loss.
If there is a conductive hearing loss, the Audiologist would refer to a medical provider for possible further testing or treatment. Other testing that might be used is imaging such as a CT Scan to help determine the nature of the conductive loss.
What Are the Treatment Options?
Once the cause of the conductive loss is determined, treatment can begin. Depending on the cause this may include one or a combination of the following treatment options:
- A simple removal of an obstruction in the ear canal.
- Surgery to repair a damaged ear drum, remove a mass from the outer or middle ear, or repair middle ear bones or ossicles
- Placement of a tube in the eardrum to aid in drainage of fluid and pressure equalization in the middle ear.
- Medication to help improve eustachian tube function and dry up moisture in the middle ear cavity or a possible antibiotic if there is infection involved.
- Amplification. Sometimes medical management is not feasible or not able to treat the problem such that hearing returns to normal. In these instances the individual may need help through amplification which can be accomplished in many different ways depending on the individual’s needs. The most important aspect of receiving help through amplification is that they seek treatment through a qualified professional who can guide them in determining the best device possible for their unique needs.
Conductive Deafness FAQs
Does conductive hearing loss get worse?
If left untreated, conductive hearing loss can definitely get worse. Depending on the nature of the loss, it can also lead to life threatening disease. It is very important that if you are experiencing symptoms of conductive hearing loss, you seek medical attention. You can do so by contacting your primary care provider, and or your Audiologist. Both can help guide you to the necessary treatment needed.
Is a conductive hearing loss permanent?
Some conductive hearing loss is permanent but frequently conductive hearing loss can be treated. Sometimes that treatment will lead to a complete recovery of hearing and other times it will help improve your hearing ability but still have some loss. The most important thing is that it is treated such that it does not progress causing even more problems and/or possible injury to the individual.
What does conductive hearing loss feel like?
Conductive hearing loss can take many forms and present itself in many ways. The most common descriptions of conductive hearing loss are the following:
- Ear(s) that feel stuffy or full.
- A muffled or dull sound
- Hearing through a barrel or sound that is hollow
- Pressure in your ear(s) or head
- Pain or otalgia
- General decrease in hearing ability
- Hearing popping or cracking in your ears
Managing Conductive Hearing Loss
In conclusion, proper management of a conductive hearing loss first begins with proper diagnosis of the loss then identification of the cause. Once this is determined, the individual can be directed to the best, most appropriate means of remediation. This may look different for each individual as we all know that no 2 bodies are the same! And, likewise, no two ears are the same either!
If we refer back to our original analogy that conductive hearing loss is like having a “roadblock”, the best course of action is to first identify what type of blockage it is, find the best team to either remove or repair the blockage or breech, and if that is not a possibility, find someone to help you get a “vehicle” with enough power to get you through, around or over the “blockage” so you can continue down the path/road that you desire!
