Hearing aids

I am on a fixed income I am paying into two health insurances, Medicare and UnitedHealthCare, and I am unable to get a much needed hearing aid. Why is a hearing aid not consider to be a health need? It is a necessity to be able to hear, it is very dangerous to be unable to hear. I know first hand, I been to three different companies for an hearing aid and the price is extremely high especially for those on fixed incomes?