Is the incident in which you lost partial hearing fully documented? If not, try proving it 20-30 years hence.
Here's a suggestion. Free. Take one of those no-cost hearing tests. They may be able to tell you what range of hearing loss you suffer from and give you some idea of what to do.
Hearing aids may run $5K-for a good one.
I was diagnosed at 30 percent loss on exit. I think I can get the hearing aids paid for.