Some of you may find this interesting. If you go to this page:
You can watch an x-ray movie of a famous phonetician pronouncing a series of phonetically interesting nonsense words. What you want to watch is the translucent soft tissue, specifically the lips, the tongue, and the velum. The velum is this huge thing you will see flopping up and down in the back of his mouth. It's what opens and closes the nasal passage so that air can or cannot go up to the nose. The uvula is the tip of the velum and it's the little thing that hangs down in the back of your throat in cartoons drawings.
The lips will only move in a big way for [p] and [b]. The tongue will bounce up to the front for [t] [d] and [n]. And then the back of the tongue will move up for [k] and [g]. Most of us have no idea what we do with our mouth in order to speak. For instance, most of us don't even know our velum exists, and yet there it is carefully and precisely controlled for each one of these words. And notice how fast everything moves. This movie is of very careful speech and it's lightning fast. At normal rates of talking, we can get out 4-5 syllables a second. It's quite stunning.
This is one of the reasons that most of the breakthroughs in teaching primates human language came after they switched to sign languages. Non-human primates vocal tracts just don't work quite like this, but their hands are just as fine-tuned.