Final answer:
Conductive hearing loss occurs when there is an issue with the transmission of sound through the outer or middle ear to the cochlea, which is not impaired. Common causes include blockages or damage to the auditory structures, except for the cochlea and the inner ear nerves. The correct option is 1).
Step-by-step explanation:
The type of hearing loss that refers to a problem with the ear canal in the outer ear or the bones of the middle ear, while the cochlea of the inner ear retains normal functioning, is conductive hearing loss.
This condition arises when there is an issue in the delivery of sound energy to the cochlea. Common causes for conductive hearing loss include an obstruction in the ear canal, a perforated tympanic membrane, issues with the ossicles, or fluid in the space between the eardrum and the cochlea.
Damage to the middle ear can be partially alleviated with hearing aids that conduct sound through the skull, but they do not amplify sound within the ear canal as other hearing aids do. Option 1) is the correct one.