My friend found her old hearing aid, 14 years after getting her CI.
She tried it on and she did hear something but the quality was very weak compared to her CI.
Of course, the tech in her HA Is considered old now.
The CI is simulating the nerve otherwise the CI wouldn’t work.
A young person who goes to my Deaf Centre has a ABI which looks like CI but his nerve doesn’t work so a CI wouldn’t work.
A CI is just a replacement for the cochlear and not the nerve.