Another one I'm not sure how to fully explain: closing the nose without touching it.

I can fully block smells or breathing by doing something that feels like inflating a zone between the top of the mouth and the nose. When speaking it will sound as if I am pinching my nose without hands. Comes in handy when having to face horrible smells.

I assume everybody can do it but many don't know how.

https://www.reddit.com/r/TooAfraidToAsk/comments/ysd5o2/is_i...

Everybody who can speak can do it because that's what you do when you say [k] or [g].