Conductive Hearing Loss

1. Everyday sounds are perceived as softer
2. Better hearing in one ear than the other
3. Difficulty hearing discussions (e.g. on the phone)
4. The quality of sound is less clear or sharp
5. High and low sounds are reduced
6. Feeling of pressure in one or both ears
7. A foul odor coming from the ear canal

The underlying causes of conductive hearing loss are frequently classified by the impacted anatomy: the outer ear and ear canal versus the middle ear. Some causes are quite common (e.g. impacted earwax), while others are rare (e.g. cholesteatoma).

1. Impacted earwax (cerumen): This is a common cause of temporary conductive hearing loss, often made worse if you attempt to dislodge earwax from your ear canal with a cotton swab. Excessive wax can prevent sound from traveling from your outer ear to your inner ear.
   
   
2. Infection of the outer ear (otitis externa): This infection of the skin of the external ear canal can cause conductive hearing loss when swelling and debris block the canal. The most common pathogens that cause otitis externa are Pseudomonas aeruginosa and Staphylococcus aureus.
   
   
3. Squamous cell carcinoma: Most squamous cell carcinomas of the temporal bone impact people in their 50s to 60s. This is the most common cancer of the external ear canal; about four times more common than basal cell carcinomas in this area. While discharge from the ear is the most common symptom, bleeding, earache, and conductive hearing loss also frequently occur. 
   
   
4. Eustachian tube may be blocked. The Eustachian tube links the back of your nose to the middle ear. Eustachian tube dysfunction may occur when the mucosal tube lining swells up or the tube doesn’t open or close properly. Temporary dysfunction is a common side effect of flying on an airplane when you have a head cold or swimmer’s ear.
   
   
5. Eardrum perforation: Infections or trauma can cause a hole to develop in your eardrum, resulting in diminished hearing in the impacted ear. Inserting an object too far into your ear, extremely loud noises, a blow to the ear, head trauma, or changes in air pressure (barotrauma) experienced during an airplane flight or scuba diving can cause a perforated eardrum.
   
   
6. Infection (otitis media): Several types of inflammation can impact your middle ear. Chronic suppurative otitis media is a persistent ear infection that causes tearing or perforation of the eardrum. Otitis media with effusion (fluid in the middle ear) is the type most commonly associated with hearing loss, ringing in the ears (tinnitus), vertigo, and earache. In adults, otitis media is more common in individuals with impaired immune systems.
   
   
7. Otosclerosis: This rare, abnormal growth of one of the tiny bones of the middle ear (stapes bone) prevents proper functioning of the structures in your ear. Presumed causes are inflammatory (e.g. autoimmune processes and measles virus), genetic, metabolic, and hormonal. This condition most often impacts individuals ages 15 to 40 and is twice as common in women as men. According to a 2009 study, 18–22% of conductive hearing loss cases are attributed to otosclerosis.
   
   
8. Cholesteatoma: Most often associated with ear infections, these abnormal, noncancerous skin growths can develop behind the eardrum in your middle ear. They often develop as a cyst or sac, and they’re associated with chronic ear infections. As the growth increases in size, it can damage the delicate bones of your middle ear.
   
   
9. Paraganglioma: Also called glomus tympanicum, this is the most common primary neoplasm of the middle ear, and the second most common tumor of the temporal bone. It most often affects women in their 50s to 60s. In addition to causing ringing in the ears, the mass in the middle ear prevents sound waves from passing through the middle ear to your eardrum, resulting in conductive hearing loss.
   
   
10. Temporal bone trauma: Blunt head injuries (e.g. sustained in motor vehicle accidents) can damage the middle ear and eardrum, in addition to injuring the brain, inner ear, and facial nerves. In conscious patients, hearing loss is immediately apparent and the most common primary complaint they report after temporal bone trauma. As many as 40% of individuals with a head injury experience hearing loss that may be accompanied by ringing in the ears.

The following tests may be used to diagnose conductive hearing loss. Additional tests are used to diagnose underlying diseases that result in conductive hearing loss.

1. Otoscopy: During this common test, your doctor will gently insert an otoscope in your ear to view your eardrum and ear canal. This will help determine if you have an injured eardrum, foreign bodies in your ear canal (e.g. impacted ear wax), or a middle ear problem. Your doctor will look at the color of your eardrum (red, white, yellow), translucency (transparent, opaque), and its position (retracted, neutral, or bulging).
   
   
2. Weber test: During this test, a tuning fork is struck and placed on the crown of your head. You’ll be asked if the sound is louder in your right ear, left ear, or the middle. If you have normal hearing, you’ll be able to perceive the sound equally in both of your ears. If you have conductive hearing loss in one ear only, you’ll hear the sound louder in the affected ear.
   
   
3. Tympanometry: A probe-like device is placed in your ear to determine if there’s fluid, abnormal pressure, or a growth in your middle ear; a perforation or scarring of your eardrum; or lack of mobility or other issues with the small bones of your middle ear. While the test only takes about two minutes for both ears, you can’t move, speak, or swallow while it’s being conducted.
   
   
4. Pure-tone audiometry: This test is used to assess hearing thresholds to determine if your hearing levels fall with normal limits.  

Unlike sensorineural hearing loss which is permanent, conductive hearing loss may be temporary and resolve on its own, or can be corrected surgically or medically. Treatment varies depending on the underlying cause.

1. Impacted earwax: Warm water irrigation is a safe method for removal if there is no history of infection, perforation of the eardrum, or prior ear surgery and if it’s performed by a medical professional.
   
   
2. Infection of the outer ear: The ear canal is debrided, followed by application of eardrops. If the infection is severe, a wick is placed in the ear for two to three days to ensure delivery of the medication. In addition, oral antibiotics may be helpful if the infection is severe. Hearing loss typically resolves after the inflammation subsides.
   
   
3. Eardrum perforation: In most cases, the hole heals on its own as long as the ear canal is kept dry. If the ear becomes infected, antibiotic ear drops or oral medication will be prescribed. If the eardrum doesn’t heal within two months, tympanoplasty may be required. This surgery involves using different types of grafts to repair the perforation. Tympanoplasty is used most often when a chronic infection caused the perforation. A 2015 study indicated a success rate of 86.6% for restored hearing function in individuals who underwent this procedure.
   
   
4. Infection: Myringotomy is used to release middle ear fluid, enabling sound waves to reach your inner ear. During this procedure, a small incision is made through the layers of your eardrum. The fluid is suctioned from the middle ear through the incision and a culture may be sent to a lab to determine if a bacteria or virus are present. Ventilation tubes are often used to permit the incised eardrum to remain open, thereby allowing better drainage of the fluid.