When saying letters our mouth, tongue, teeth and lips do different things. I’m amazed how much we use the roof of our mouth when talking (14 of the 26 letters).
And it makes sense why we call a, e, i, o, u “vowels“. They come purely from the throat.
(7) dghjlnt: tip of tongue touch roof of mouth
(3) csz: tip of tongue close to roof of mouth
(3) kqx: back of tongue touch roof of mouth
(1) r: back of tongue close to roof of mouth
(4) bmpy: lipsmack
(2) fv: teeth touch lip
(6) aeiou: no tongue
(1) w: etc
This makes me wonder if other languages use other parts of the mouth more or less.