This article explores the notion of “endophasia”, understood as “inner speech” or “inner speaking”, hence distinct from auditory hallucinations, and its possible absence, “anendophasia”. By analogy with findings in the visual domain related to phantasia and aphantasia, neurobiological mechanisms for endophasia are speculated upon, as well as possible consequences and associations of anendophasia.
AJ Larner (Thu,) studied this question.