Conductive hearing loss is one of two main categories of hearing loss, the other being sensorineural hearing loss. Conductive hearing loss may result from diseases that affect the external ear or middle ear structures.
Causes of Conductive Hearing Loss
Conductive hearing loss may result from diseases that affect the external ear or middle ear structures.
Problems with the external ear:
- Cerumen (ear wax) obstruction: Ear wax can be identified by a medical examination and can usually be removed quickly. This condition may actually be aggravated by cotton tipped applicators (Q-tips) that many patients use in an attempt to clean their ears.
- Otitis Externa: Often referred to as “swimmer’s ear”, an infection of the ear canal may be related to water exposure. Although the most common symptoms of otitis externa are pain and tenderness of the ear, conductive hearing loss can also occur if there is severe swelling of the ear canal.
- Foreign body in Ear Canal: This is readily identified on examination and can usually be cleared in the office. Occasionally, a brief anesthesia is required for this procedure in children. Common foreign bodies include beads and beans in children and cotton or the tips of cotton-tipped applicators in adults. Uncommonly, the foreign object is a live bug such as a cockroach which can cause itching, pain, and noise.
- Bony lesions of Ear Canal: These are benign growths of bone along the walls of the ear canal resulting in a narrowing of the ear canal which may then lead to frequent obstruction from a small amount of wax or water. These bony lesions can generally be managed with vigilant cleaning of ear wax to prevent obstruction. In rare cases these lesions require surgical removal.
- Atresia of the Ear Canal: Complete malformation of the external ear canal is called atresia. It may be seen along with complete or partial malformation of the pinna (outer ear) and is noted at birth. It is rarely associated with other congenital abnormalities and is most often only on one side (unilateral). Management of congenital aural atresia is complex. Surgical treatment may be beneficial to either reconstruct the ear canal in select cases or to implant a device that vibrates the bone of the ear directly.
Problems with the middle ear structures:
- Middle Ear Fluid or Infection (otitis media): The middle ear space may be filled with fluid instead of air. (link to otitis media page)
- Tympanic Membrane Atelectasis or Retraction (collapse of the ear drum): Poor eustachian tube function may also result in excessive negative pressure behind the eardrum causing the eardrum to collapse onto the middle ear bones. Severe retraction of the eardrum may necessitate ear tube surgery or a surgery to rebuild the eardrum (tympanoplasty).
- Tympanic Membrane Perforation: A hole in the eardrum due to infections or trauma may result in hearing loss as the sound vibrations are not effectively captured by the damaged eardrum. (link to perforated eardrum page)
- Cholesteatoma: This may develop when the eardrum collapses to the point that the outer skin of the eardrum grows into the middle ear and becomes trapped.
- Damage to the Middle Ear Ossicles: This may result from trauma, infection, cholesteatoma or a retracted eardrum leading to conductive hearing loss. Surgical reconstruction of the ossicular chain is often successful in restoring hearing in these cases.
- Otosclerosis: This is an inherited disease in which the bone around the stapes bone hardens and the stapes fails to vibrate effectively.
Many types of hearing loss can also be ameliorated with the use of conventional hearing aids. In addition, many implantable hearing devices are available for various types of hearing loss. An audiologist or otologist can determine the specific cause of the hearing loss, advise patients of their treatment and rehabilitative options, and help patients achieve the best possible hearing outcome and hearing related quality of life.