Conductive hearing loss is a type of hearing loss that occurs when sound is not transmitted efficiently through the outer or middle ear to the inner ear. It can affect one or both ears and may be temporary or permanent, depending on the underlying cause.
Under normal hearing conditions, sound travels through the air into the external auditory canal, causing the eardrum to vibrate. The three tiny bones of the middle ear, called ossicles, transmit these vibrations toward the inner ear, where specialized sensory cells convert them into electrical signals that travel to the brain.
Conductive hearing loss occurs when a problem in the outer or middle ear interferes with this process. Common causes include earwax blockage, fluid accumulation in the middle ear, ear infections, a perforated eardrum, and disorders affecting the ossicles.
QUICK FACT
- Conductive hearing loss can sometimes be improved or corrected by treating the underlying cause, depending on the condition.
- Bone-conduction hearing tests can help assess inner-ear function because vibrations transmitted through the skull stimulate the cochlea without relying on the usual sound-transmission pathway through the outer ear, eardrum, and ossicles.
- Treatment depends on the cause and may include removing an earwax blockage, treating an infection, or using hearing devices or surgery when appropriate.
COMMONLY CONFUSED WITH
- Sensorineural hearing loss: Hearing loss caused by damage or dysfunction of the sensory structures of the inner ear or the auditory nerve pathways. Unlike conductive hearing loss, it is not primarily caused by impaired sound transmission through the outer or middle ear.
- Mixed hearing loss: Hearing loss involving both conductive and sensorineural components.
- Bone conduction: The transmission of vibrations through the bones of the skull to stimulate the cochlea. Comparing bone- and air-conduction hearing thresholds helps clinicians distinguish conductive from sensorineural hearing loss.
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