InCall Volume Reg Tweak/s? (Looking to increase)

[Genjinaro]

Hours of google produced about a 20% increase to the dreadfully low hums of sound, emitting from my 6800.
Much thanks to Menniesyys.

But still its not enough, unless I'm in a quiet setting or 120% of my concentration is dedicated to deciphering what the other caller is saying,
I'm not going to hear them very well or at all. *Yes I'm closing my eyes fiercely as they speak *

& Yes, my hearing is excellent & my volume is at max.

Anyone have any tweaks you can recommend for me and many many others?
Even if they are a bunch of tiny enhancements or tedious I'll be very grateful to have that much more clarity.

Any help is welcomed.