I believe new hair cells come with new ribbon synapses, but I am 99% certain damaged hair cells that still exist will stay damaged. Liberman's study showed hearing loss has more to do with ribbon synapse damage then hair cell damage.Doesn't frequency therapeutics drugs repair hair cells along with ribbon damage? I'm pretty sure I read @JohnAdams discussing this.
Also the stimulation devices will most likely provide a much needed treatment until the cure it found. I know a cure is optimal, but a least a treatment is better than nothing. I am sure it will give a lot of us some quality of life back.
I can still hear up to 15,000hz
meaning I have hair cells that are basically de-nerved, and the hope is that generating new ones will help, but according to @JohnAdams regenerated hair cells won't grow where current hair cells exist.
so my damage in low-high frequencies 1,000hz-10,000hz caused by cochlear synapse damage won't repair. and I'll just get my ultra high frequencies that are near useless restored. I'll still have trouble with speech in excessive background noise and most music.
I think a more effective treatment would be to repair the ribbon synapses of the cochlea, maybe both. That's the thing.