So, my mother in law had a haunted iPhone that would only play the ringtone very softly over her hearing aids, or not at all. This is a widely reported problem with no known working solution. (I HAVE TRIED EVERYTHING YOU CAN GOOGLE). Today we migrated her to a new iPhone 16e, and it transplanted the problem from her iPhone 8! I suspect this is a messed up setting with no UI element (anymore). Is there some kind of iPhone registry viewer? Or a way to reset the audio settings to defaults?

@bert_hubert

Hearing Aid user here :
Hi. there.
Recently I bought and have been using the most advanced hearing aids available, and I purchased a different high end brand for my husband a little later., so with that in mind....

Although I am not familiar with iphones, we use androids, I am interrupting your thread with these suggestions:

1: Our HAs are adjustable using a phone app and any number of things can interfere with/screw up the settings or App. (for example, one faulty update bricked my hearing aids!!) If you haven't yet, try uninstalling, reinstalling the App, then adjusting the appropriate settings within the App.

2. Most high end hearing aids are directly compatible with a select number of android models, sand I know it's the same with iphones. That's something to check with the issuing audiologist or manufacturer. Compatible phone models are listed on the HA manufacturer website or within the App on the phone, along with troubleshooting advice.\

3. Some brands of HAs have an accessory that can be purchased to bridge the phone, a tv, or computer audio...it's worn as a pendant or set nearby the user....not sure if hers are the same but it's something to check

Edit: When all else fails contact the issuing audiologist and or the manufacturer--the HAs might be defective or need repairing