I've spent a bit of time looking at the Developer's code.
It is possible to miss one Afaik- that would be "The Seventh Sorrow," which you can gain during one of the quests. I don't remember getting any others and this one is used rather infrequently.
You get three by default at the start of the game.
label characterselect:
scene selectmenumajoris
with dissolve
$ spinalchordchoir = True
$ templeofthebody = True
$ sacredscreed = True
As for which ones speak the most it boils down to which primary facet you chose. The primary facet seems the most chatty
Apparatchik- Intimidation - Comportment
Rapport- Acquiescence - Comportment
Panoply- Acquiescence - Intimidation
The two smaller facets coming with your Facet Majoris tend to fill in the roles / provide
some but not all of information the Major facet would. That is not to say your choice is irrelevant- it deeply changes what information you get the most of and how your character comes off, but for example.
You get some of the information you'd get from
Apparatchik via the
Acquiescence facet.
Acquiescence =
Apparatchik
But with far less detail and your Auditor is far less of an Egg-Head.
Intimidation =
Rapport
But your Auditor's emotional understanding is mostly through the lens the fear emotion than holistic.
Comportment =
Panoply
But your Auditor is far less of a manipulative politician type.
The
Facet Minoris seem pretty equal in chattiness and provide observational data about the world via much different flavors of text.
Razor Wire- Paranoia, reflexes, and survival instinct.
Unto Dust- Like actively anticipating "The fall of Rome" whilst you live in unfallen, but falling Rome.

Pretty pessimistic trait.
Fortress Unbarred- Peeks into what others are thinking- sometimes past as well. Very narrative and mystical trait.
There is no internal system that ramps up or down any of the voices beyond your initial choices of which ones to pick up or not. They are all boolean. Either you have it or you don't and that is what changes which voices you hear the most!