I've got questions about oaths

I've got questions about oaths. I know that if you say oaths in your mind they're not valid but, 1. What happens if you hum the oath whether your lips are closed or not? 2. Also what if you're saying an oath in your mind but your mouth is open? (And you're not sure if you could've said it out loud accidentally or if yk you didn't say it out loud) Thank you :)