Confused about 9050"s: Microphone volume vs Sound volume

On an Apple iPhone, using Accessibility and choosing hearing devices, there is a setting for “microphone volume.” Versus the “sound volume” in the HearLink 2 app.

Since I have always had negative comments about the sound quality of my voice while on a call, I decided to adjust the “microphone volume” on the iPhone while talking to my wife. (What I quickly Learned was that both the iPhone microphone volume and the sound volume in the Hearlink 2 application are the same thing.)

So while on the call, I adjusted the iPhone “microphone volume” from say 25 to 50. My wife said that sounds horrible. So I adjusted it all the way to zero and she said, thats better but you are still muffled. So at that point is when I went into the Hearlink 2 application and saw where it also had adjusted the “sound volume” to zero.

So my confusion and ability to get good sound quality via bluetooth continues with these. Leaving them adjusted to “0” is clearly not acceptable. I’m also confused as to whether the phone microphone is in use also?

Any thoughts or help would be appreciated.