Which of the following is a progressive conductive hearing impairment?

The correct answer is indeed otosclerosis, which is characterized as a progressive conductive hearing impairment. This condition results from abnormal bone growth in the middle ear, specifically affecting the stapes bone, which impacts its ability to transmit sound vibrations to the inner ear. As the condition progresses, it leads to a gradual decrease in the ability to conduct sound, making it more difficult for individuals to hear, particularly in lower frequencies. The conductive nature of this impairment is due to the mechanical blockage or alteration in the transmission of sound waves through the ear structures.

In contrast, auditory processing disorder affects how the brain processes auditory information rather than the physical mechanisms of hearing, while noise-induced hearing loss typically results in sensorineural hearing impairment due to damage to the inner ear from loud sounds. Presbycusis, associated with aging, also primarily leads to sensorineural hearing loss rather than conductive. Hence, otosclerosis stands out as the only option that indicates a specific condition causing progressive conductive hearing loss.