For me, I don't narrate or everything I'm doing but I might think and hear my own voice in my head saying "OK, I'll just stick the kettle on and I'll empty the dishwasher while that's going", but I don't hear things like "lift up the kettle, take off the lid, turn on the tap, fill the kettle, turn off the tap, put the kettle down, switch the kettle on" etc. Maybe it depends on how familiar a task is to me, I'd say it's more abstract most of the time but sometimes it helps me plan things.
I think some of my thoughts are subconscious, like I don't always know what I'm about to say, but if I've been trying to put my thoughts in order during a conversation, I might have an idea of what's coming. Planning what I'm going to say never works though, I stumble on actually saying it out loud, so I just let it come organically.
Mine is mainly just chatter, really, like having a friend you natter away to. I do hear that at my normal talking speed. Some thoughts, I'm conscious of but don't hear them.
It's so weird and fascinating isn't it, I love that everyone has their own experience!