The "Adam's Apple" we use to call it. We all have one. You know, that place in the neck that sticks out in the front, ever since Adam took that first bite, and a piece of the apple got stuck in his throat. The larynx I believe it is officially called. It is especially adapted to act as a vibrator to the air that passes thought what we now call the "voice box". Phonation (sound) and articulation (speech) are the processes by which we learn to speak.
There are specific speech nervous control centers in the brain as well as various breathing control centers of the brain. These centers, along with resonance structures of the mouth and nasal cavities produce our speech. The stretching and motion of the vocal cords are central to this activity. You then add the soft palate, the tongue, and lips to this process of air movement, and...walla...you have speech.
What a wonder it is.
