It's probably more that it's difficult to prove something damaged his hearing if it's not mechanical. ACC cover hearing damage, but not congenital hearing loss or Meniere's disease, etc.
ACC draw a very hard line. For example if you dislocate your shoulder in an accident they pay for it to be fixed but if they think it dislocated due to, say, rheumatoid arthritis or EDS then you are not covered.
Maybe you should make yourself a Neocities page, that's like pre-social media internet...