I talk out loud too. My mom used to do it also, having conversations with herself. I do it more when I’m under stress, but I’m also aware that it makes me look mentally ill to anyone who happens to witness it, so I am careful to rein myself in when in an area where someone might overhear me. I don’t know if this is an ADHD-specific trait, or part of another mental disorder. I often wonder if my mom had ADHD. I know she had some OCD going on–repeatedly checking to make sure stove burners were off or doors were locked, saying the words “off” or “locked” repeatedly while doing it.