I read a research paper quite some time ago that most inner monologue is articulated at least partially by the mouth, throat, & tongue, and can be detected. Might be a better approach than having a chip in my brain.
what's fascinating is apparently there's a connection with schizophrenia, where the "voices" are actually the person saying things to themselves at a level too low for other people to hear
If I find the article I will update.