Conductive hearing loss occurs when sound cannot properly travel through the outer or middle ear, often leading to muffled hearing, ear pressure, or temporary hearing changes.
What Causes Conductive Hearing Loss?
Conductive hearing loss happens when the natural movement of sound through the external ear or middle ear is blocked, and the full sound does not reach the inner ear. Conductive loss from the exterior ear structures may result from:
- Earwax—Your body normally produces earwax. In some cases, it can collect and completely block your ear canal, causing hearing loss.
- Swimmer’s ear—Swimmer’s ear, also called otitis externa, is an infection in the ear canal often related to water exposure or cotton swab use.
- Foreign body—This is typically a problem in children who may put common objects, including beads and beans, in their ears, but it can also be seen in adults, most often by accident, such as when a bug gets into the ear.
- Bony lesions—These are non-cancerous growths of bone in the ear canal, often linked with cold water swimming.
- Defects of the external ear canal, called aural atresia—This is most commonly noted at birth and often seen with defects of the outer ear structure, called microtia.
- Middle ear fluid or infection
- Ear drum problems
Conductive loss associated with middle ear structures includes:
- Middle ear fluid or infection—The middle ear space normally contains air, but it can become inflamed and fluid-filled (otitis media). An active infection in this area with fluid is called acute otitis media and is often painful and can cause fever. Serous otitis media is fluid in the middle ear without active infection. Both conditions are common in children. Chronic otitis media is associated with lasting ear discharge and/or damage to the eardrum or middle ear bones (ossicles).
- Ear drum collapse—Severe imbalance of pressure in the middle ear can result from poor function of the Eustachian tube, causing the eardrum to collapse onto the middle ear bones.
- Hole in the eardrum—A hole in the eardrum (called the tympanic membrane) can be caused by trauma, infection, or severe eustachian tube dysfunction.
- Cholesteatoma—Skin cells that are present in the middle ear space that are not usually there. When skin is present in the middle ear, it is called a cholesteatoma. Cholesteatomas start small as a lump or pocket, but can grow and cause damage to the bones.
- Damage to the middle ear bones—This may result from trauma, infection, cholesteatoma, or a retracted eardrum.
- Otosclerosis—This is an inherited disease in which the stapes or stirrup bone in the middle ear fuses with the bones around it and fails to vibrate well. It affects slightly less than one percent of the population, occurring in women more often than men.
