Final answer:
Cochlear implants can restore hearing for those with a damaged cochlea by stimulating the auditory nerve, but they will not be effective if the hearing loss is due to an abnormal auditory nerve.
Step-by-step explanation:
Cochlear implants are devices that can restore hearing in individuals with nonfunctional cochlea. When considering the types of hearing loss that cochlear implants can address, it's important to understand that these devices function by bypassing damaged hair cells in the cochlea and directly stimulating the auditory nerve. Hence, they are most effective in cases where the inner ear or cochlea is damaged but the auditory nerve is intact. Specifically:
- Hearing loss resulting from absence or loss of hair cells in the organ of Corti can be restored by a cochlear implant, as this is the exact issue that cochlear implants are designed to overcome.
- Hearing loss resulting from a fracture of the cochlea can also be potentially restored, as the implant can take over the cochlea's role in sound transmission.
- Hearing loss resulting from damage to bones of the middle ear might be better addressed with different types of hearing aids that amplify sound, rather than with a cochlear implant.
However, hearing loss resulting from an abnormal auditory nerve would not be restored by a cochlear implant. This is because the effectiveness of a cochlear implant depends on the ability to stimulate a functional auditory nerve. If the auditory nerve itself is damaged or abnormal, the implant will not be able to transmit sound signals to the brain properly, rendering it ineffective in such cases.