If you don’t mind looking like a teenager listening to music, I suggest you try an iPod touch (the cheapest model) with the free Ear Machine software. This has worked well for my dad for the last two years, better than the sequence of hearing aids that he spent $8,000 on.
For less than $200, you have something that you can compare the more expensive solutions to.
Thanks for an “outside the box” suggestion. For a few years now I have been wearing headphones listening to the TV. Now, no one complains how loud it is and I can understand what Bernadette is saying in Big Bang Theory episodes.