Like I said earlier: the more I read, the more problems I see. Initially I figured: "if only science is able to understand the mechanism that happens in birds and fish, which seems to have been lost somewhere in mammals during evolution". Understand and copy this for humans.
Now I am starting to see it is very complicated.
I also read that the hair cells and the location in the cochlea of these regenerated hair cells is not perfect. What I found very positive news is that when the hair cells form also neurons connect. I don't understand why this happens but this must be positive.
I read this article
@Nick Pyzik mentioned, about neurons forming and connecting again to hair cells spontaneous. Apparently this only just has been discovered in 2015. But I want to remain positive. I still believe that Hearing Health Foundation, Action On Hearing Loss, Harvard, Stanford, other universities and particularly private companies are putting in the effort and money because they must have concluded that hearing restoration could be feasible.
For private companies I feel that assessing on forehand is paramount. If investing in a venture (hearing restoration) is able to generate a return, is one of the most important steps in the whole process of deciding whether to step in or leave it.
I am not sure why I made the grammar so complicated