It's just really hard to tell Beste. I know there are researchers out there working on stem cell repair for hearing loss. There are two researchers who have the right idea about using stem cells for auditory nerve damage. I'll link their information below.
A study performed in 2015 by the University of Kyoto showed that placing differentiated stem cells onto the glial scars that form after damage has taken place inside the regions where the auditory neurons are, showed much better results in regeneration than transplanting the stem cells into the glial scars. More information linked below about that.
I'd reccomend checking out the Otostem website I linked below. It's basically a supergroup of researchers who have partnered together to create treatments with stem cells for hair cell and auditory nerve hearing loss. Although there hasn't been any updates on the site, it's still very cool.
It's best to just read into the publifications of researchers associated with this issue.
(1) Marcelo Rivolta - Professor of Sensory Stem Cell Biology - The University of Sheffield: https://www.sheffield.ac.uk/bms/research/rivolta ---- http://www.otostem.org/
(2) Charles Liberman - Harvard Medical School - Harold F. Schuknecht Professor of Otolaryngology
Vice Chair of Basic Research, Department of Otolaryngology - Massachusetts Eye and Ear - Director, Eaton-Peabody Laboratories
Senior Scientist: http://www.masseyeandear.org/research/investigators/l/liberman-m-charles
(3) Testuji Sekiya - Department of Otolaryngology, Head and Neck Surgery - Kyoto University Graduate School of Medicine:
http://www.kyoto-u.ac.jp/en/research/research_results/2015/150616_1.html -----http://www.labome.org/expert/japan/kyoto/sekiya/tetsuji-sekiya-902287.html
Articles you might be interested in reading:
(1) http://www.hearingreview.com/2016/02/plasticity-brain-compensates-damaged-auditory-nerve-fibers/
(2) http://www.hearingreview.com/2014/0...anism-nerve-fiber-loss-discussed-asa-meeting/
(3) http://hyperacusisfocus.org/innerear/
(4) http://www.tinnitus.org.uk/tinnitus-and-hidden-hearing-loss
*I would include more publifications and documents but it's actually very rigorously time consuming doing all the searching/copying/pasting/organizing on an iphone. Wishing I had my laptop, but I'm unfortunately working at a golf course right now.
