Hi George. As Neville pointed out it’s hair cells (not actual hairs) in the cochlea. Google on these terms:
hair cell regeneration, Frequency Therapeutics, Regain Hearing Project, Albert Ellis, Hough Institute, Hearing Health Foundation. That’s just to start with.
You hear wildly different forecasts as to when a treatment might become available. Ranges from a couple of years to decades. Some people around here will say ‘never’, which is fair enough because we’ve been fed news of ‘breakthroughs’ for years. I think it will happen. I’m just hoping I’ve got enough supporting cells left to work on when it does.