I have central auditory processing disorder, capd. Seeing a visual is instantaneous, clear, easy. People speaking is torturous, brain can’t process, requires lot of work, confusion, translating. For me, visuals are external, but even external sounds become internal, physical. Activation of the limbic system, anxiety, fear, can lead to hearing voices. Prefrontal cortex, I think, is where brain stops internalizing sound as stress, fear. Why some people with adhd who hear voices take a small, mild dose of Ritalin at night. Ritalin means less limbic, less fear.

Not an answer to your question, but I think different areas of the brain process sound, visuals. Different mechanisms. I’d be interested to know if someone could shed light on this.