What causes conductive hearing loss?

• A. When sound waves cannot pass through the outer or middle ear.
• B. Damage to the cochlea or auditory nerve.
• C. The Rinne test compares bone conduction and air conduction.
• D. It provides a legal record of care.

Answer: (A)

Conductive hearing loss happens when sound cannot be conducted efficiently through the outer or middle ear. The outer ear (ear canal and eardrum) and the middle ear (the ossicles) are responsible for delivering sound energy to the inner ear. When a blockage or disruption occurs—such as a buildup of ear wax, an ear infection with fluid in the middle ear, a perforated tympanic membrane, or problems with the tiny ear bones like otosclerosis—the transmission of sound energy to the inner ear is reduced. The inner ear and the hearing nerve remain intact, which is why bone conduction can seem relatively clearer than air conduction in these cases. The other options point to inner-ear (sensorineural) damage, a test that's used to differentiate types of hearing loss, or an unrelated administrative purpose, none of which describe a blockage or dysfunction in the outer or middle ear.