What can lead to conductive hearing loss?

Conductive hearing loss occurs when there is a problem in the ear that prevents sound from being conducted effectively to the inner ear. Obstruction in the ear canal is a classic cause of conductive hearing loss because it can block sound waves from reaching the tympanic membrane (eardrum) or the ossicles (small bones in the middle ear). This obstruction can arise from various factors such as earwax buildup, foreign objects, or fluid accumulation due to infections, which interfere with sound transmission.

In contrast, the other options address issues related to the inner ear or beyond. An infection in the cochlea pertains to sensorineural hearing loss, which originates from problems affecting the inner ear or auditory nerve. Similarly, deterioration of the auditory nerve and damage to brain centers responsible for hearing relate to the central processing of auditory information and would not typically result in conductive hearing loss, as they do not involve the physical mechanics of sound conduction through the ear structures. Thus, obstruction in the ear canal directly impacts the conductive pathways, making it the correct answer in identifying a cause of conductive hearing loss.