Conductive hearing loss is a form of hearing loss where the transmission of sound from the environment to the inner ear is impaired, usually from an abnormality of the external auditory canal or middle ear. This form of hearing loss can be temporary or permanent. Untreated chronic otitis media (ear infections) can lead to conductive hearing loss. If fluid is filling the middle ear, hearing loss can be treated by draining the middle ear and inserting a tympanostomy tube.
The other form of hearing loss is sensorineural hearing loss, hearing loss due to abnormalities of the inner ear or the auditory division of the vestibulocochlear nerve (8th cranial nerve). Historically, this condition can occur at all ages, and is usually permanent.
When should a hearing test be performed related to frequent infections or fluid?
A hearing test should be performed for children who have frequent ear infections, hearing loss that lasts more than six weeks, or fluid in the middle ear for more than three months.
There are a wide range of medical devices now available to test a child's hearing, Eustachian tube function, and flexibility of the ear drum. They include the otoscopy, tympanometer, and audiometer.
Do people lose their hearing for reasons other than chronic otitis media?
Children and adults can incur temporary hearing loss for other reasons than chronic middle ear infection and Eustachian tube dysfunction. They include:
- Cerumen impaction: compressed earwax
- Otitis externa (swimmer’s ear): Inflammation of the external auditory canal
- Cholesteatoma: A mass, usually resulting from chronic otitis media, of horn-shaped squamous cell epithelium and cholesterol in the middle ear
- Otosclerosis: A disease characterized by the formation of soft, vascular bone in the otic capsule (bony labyrinth) of the ear, leading to progressive conductive hearing loss. It occurs due to fixation of the stapes (bones in the ear) and is more prevalent in adults
- Sensorineural hearing loss: May result because of involvement of the cochlear duct
- Trauma: A trauma to the ear or head may cause temporary or permanent hearing loss.