I don't think the ability to create hair cell regeneration will be enough. I think we will also need to understand why the hair cells die or are destroyed and develop the ability to prevent that from happening also.
If not, I could see a situation where many people would need to have to have their hair cells constantly replaced -- and even if that becomes feasible wouldn't it be likely that there would be times when many hair cells have died and haven't been regenerated yet? I imagine people in that situation would still have periods of time when they were not hearing well. Also they may have constantly fluctuating levels of hearing which might require many pairs of hearing aids depending upon where they were in their hair cell regeration cycle.
I'm still in favoring of learning how stem cell therapy could help reverse hearing loss -- but I think the solution is much more complicated then merely replacing non-working hair cells for many people with hearing loss.
(Exceptions: people who have hearing loss as a result of ototoxicity (bad reaction to pharmeceutical drugs), noise damage or inner ear concussions from an accident. Those people could probably benefit from a one-time application of stem cell therapy that would replace the hair cells. )
kokonut -- thanks for the link to the article -- very interesting. That is the most thorough description of how the inner ear works that I've ever read (well skimmed anyway
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