two types of thought.. intentional deliberate thought.. planned activity to work through a problem, or rehearse a pending conversation.. would be like hearing my own voice, but before travels through air and is picked up and interpreted by an ear.

spontaneous random, or seemingly random thoughts arise with no voice or speaking associated at all. mostly words, but "impressions" of words, or a phrase, then rendered into a concept. sometimes the sound, but not spoken. it's internal hearing. clauradience. sometimes it's the sound of a frequency. sometimes the appearance of a word. but rarely an abstract symbol. mostly word based thought.