My Mom, peace be with her, had several of these digital "hearing aids", costing much more than her analog one, yet not even one of them worked properly, nor was it possible for the folks purportedly capable of adjusting and calibrating them able to do anything with them.

AFAIK, she spent somewhat less than $25k on three of them, from different vendors, including adjustments and "calibration," yet they never worked properly with the phone, meaning she had to take them out in order to understand whoever was on the phone, and, if she wanted to understand what was being said, she often had to take it out as well. From my own observation over a decade or so, the "digital hearing aid" is not an aid, impairs hearing, and is only barely digital.

I'm gradually losing my hearing these days, but I'm not upset about it. I can turn up the stereo as far as I need, I don't need to see or to hear the TV, and the people I need, generally, to understand, know that I'm not so able to understand them as I once was, so they kindly take the necessary pains to ensure I've understood what they've said. It's not as bad as one might imagine, yet, but I see the writing on the wall ... so long as I wear my glasses.

RE