voices?

My brain never stands still, and while it churns I can hear the voices chatter...but I can only hear them in my head not in my ears...so how is it that I can hear it at all? There are distinguishable voices using noticeable inflections but it's not aloud. Are the hearing portions of my brain active when I listen to these tones in order to transmit the idea within? It's like thinking about infinite space; dwell on it too long and a neighbour will call the mad house on you.