I have severe loss in my left ear from flying reciprocating aircraft with the left side window open. And age related loss in the right er (83 years).  I am trying every HA I can find cheap on EBay.  Linx2 9-62, Canta2, and several cheap amplifiers.  The amplifiers are just as good as the $3000 HAs for hearing in public spaces which is where I need them.  But they are not good.  Best so far has been the Linx2 9-62 but it it still amplifies the noise as much as the voice so isnt really a help.