Most of the time I think with my own voice, but sometimes when I've been watching a lot of videos from the same creator I'll start thinking with their voice and speech patterns. This was moderately annoying when I started hearing my thoughts being narrated by Jacksepticeye's high-pitched Irish voice.
To me it's like the voice gets beamed into my head, bypassing my ears. I don't "hear" it, it doesn't "sound" like anything but the words are there. It can pronounce things different or with accents but it isn't a real voice.
I can only internally see the contours of objects if I don't focus on them. My inner monologue is my own voice unless I have been with my friends some time, then my inner monologue mimics their voices
Same here. I'm not aware of a term for it, but I've always been a bit self-conscious about the fact that I don't know what my inner monologue sounds like. I've tried giving it a voice, and it never sticks.
Weirdly, Masc Voice and Femme Voice kinda just switch in and out. I have no clue if there's a correlation, or if my brain is still just adjusting, because Femme is definitely the more dominant of the two, but I have to use Masc for work and such, still, vocally.