Have you never talked / mouthed without making sounds? Never even as a kid when something made you mad and you paced around the room think-saying shower thoughts to get back at that person? Even as an adult I probably mouth a sentence or two e.g. "What the fuck is this" when looking at AI output 3-5 times a week

It does feel a little weird to do it voluntarily when not emotional, but that'll be solved as soon as Claude fucks something up :)