They see visual symbols in their heads but nothing audible. They have no "inner voice" but still have thoughts, they're just visible
Ah! that makes so much sense, because I can't see anything visible in my head, even if I try to imagine something "visual" I only can get the name of it. Like when I think about seeing or visualizing an apple, all I can "see" is thinking of the word apple. Though I have been training for years now to visualize things. I can now visualize a short 1-2 seconds video. almost like watching a video on your phone. but I can't hold it for longer than 1-2 seconds. yet.