I'm well into what I hope is the final review of my WIP. Currently, I'm fine-tuning the voices of my 3 major characters. Reasonably happy with that part of the revision.
Because of the nature of my story, each of these MCs spends significant time alone. Therefore, internal monologues/thoughts are important.
I've successfully attributed unique voices to these characters, but I haven't changed their thoughts to match their spoken voices.
My reasoning for this relies on several psychological studies, which can be summarised as follows: A person, when speaking remains unaware of the speech differences heard/interpreted by the listeners.
On that basis, I have differentiate the MCs' voices, but have left their thoughts unchanged. For example:
Spoken: "Piss off ya dumb prick. Told ya yesterday I ain't sellin' t' ya."
Thought: I haven't time to deal with this now.
Would appreciate comments.