A rare variation of the phenomenon in which people’s senses are intermingled involves the mind’s eye seeing speech in captions. Scientists believe the condition arises from excessive neural connectivity and stimulation
It's like a mental HUD. Sometimes there's even an internal monologue like the enclopedia checks in Disco Elysium; though it's my voice, not that cool narrator's voice.
14 point Times New Roman font (or, well, at least a font with sarifs) above or below whatever I'm looking at, giving the name of and a short description of the thing, or what words I am hearing being spoken.