Buying a generic hearing aid over the counter without professional adjustment isn’t likely to do you much good, regardless what you paid for it.
A hearing aid isn’t just an amplifier, making everything louder, it only boosts the volume of the frequencies where you’re deficient. It takes testing to identify those frequencies.
It’s not just the old tone test, where they play a tone louder and louder until you finally hear it, there also are discrimination tests that involve someone saying words to you and you repeating them back to them. From that they can tell what parts of speech you’re having trouble understanding, and make adjustments for that.
Roll all that together and they know how to adjust your aid so you get the most out of it. You’re probably better off with a cheap aid that’s been properly calibrated than an expensive one that hasn’t been.
Tried a hearing aid advertised on TV. It did amplify but failed the part where it was supposed to pair with my phone. Called tech support and found that they paired nicely with Google phones but not with Iphone. So I sent it back — they honored their warrenty. Then I went to Costco.
I did pay more $ 1300 for two units, but they tested me and adjusted the devices. At first I had to lower their effectiveness. Easy on the phone app. Next I had to change the frequency response, also easy with the app. I had to lower the high frequency because that was where all the noise was. And my wifes voice was midrange, so I raised that. Now I find I am happy — as a bonus, I can listen to music and cell calls over my hearing aid or switch back to the phone.
Costco did a very good job and they will clean the devices while you shop if you go in regularly. But you have to be a member so there is that.
Have signal generator and oscilloscope, can test.