I've always talked to various (mostly dead) people in my head, or sometimes out loud. For instance on everything related to music I very often talk with J.S. Bach (a good approximation for God in this case). I also almost always have long dialogues with authors of the books I'm reading. These days I'm reading Ibn Khaldun, therefore I sometimes speak with him about the world, or Islam (of which he was a true "doctor"), or politics, etc.

However usually imagining a telepathic communication of some sort is enough. I rarely need to imagine them as actually present in the room if ever, unless it's to "show them" something in particular.