Chosen Solution
My wife’s iPhone 6s recently started to sound very quite when she was talking with people. She thought it was just her, but I verified the low earpiece volume. Proximity sensor, front facing camera both work properly. I have tried multiple fixes. Changing language setting (En to UK and back). Replacing the earpiece, and cleaning the screen. It also has the most up to date iOS. Also, I have done the voice memo test to see if it works better, but unfortunately it is still the same low volume. The only thing that I know of and have not tried, is poking a small hole in the left portion of the screen. I see this as a last ditch effort, and prefer to leave the mesh intact. Any other options that may work for me? Thanks in advance.
For some of my repairs in the past, I have fixed this issue by replacing the whole front facing camera/light and proximity sensor flex. Have you tried replacing that yet? Some flexes can still properly connect and power all components but one. For example I have had a few phones come in with the same issue as yours, but I replace the flex and all is well. I replace the flex even though all the rest of the components seem to be working, but sometimes they can just ware out.
