Exploring Hearing Aid integration in Apple’s iOS system (MFi).

Additional features that MFi offers that traditional hearing aids can’t.

Made for iPhone hearing aids connect to iPhone, iPad, or iPod touch so you can stream audio, answer phone calls, adjust settings, and more.

Source: (https://tidbits.com/2020/05/30/exploring-hearing-aid-integration-in-ios/)
The author describes his experience in setting up and using “Made for iPhone” hearing aids. The integration works, but in daily life not every usage aspect is obvious.