Here's why:

* Lungs: The lungs provide the air that powers speech.

* Diaphragm: This muscle helps us control the flow of air from the lungs.

* Vocal cords: These folds of tissue vibrate when air is forced through them, creating sound.

* Mouth, tongue, and lips: These structures shape the sound into words.

So, while we don't have a single machine that does all the work, our vocal tract is a complex system of interconnected parts that work together to allow us to speak.