We never talked about voice volume while calling, always focusing on ringer and notification volume.
The volume you hear from the speaker on the top of your cellphone is controled by "Voice volume" or "Bluetooth voice" when you use a BT headset.
I had noticed the possibility you have some issues when you charge the battery while going out or when you come back at nighttime or weekend's daytime. Therefore I planned the step to check 3 macros together and to evaluated them comparing each other. However, you would like to jump to higher stage and skip it.
These macros are gone away under my control. So, I have nothing to do anymore. All I can do is answering just a simple question. The hands on style is no longer available, unfortunately. However, you had experienced enough case studies in this thread. It has many tips to solve your problems by yourself.