A sketch of larynx is shown below:
Larynx is that part of throat which is responsible for producing sound. Inside larynx, there are two vocal cords, which are stretched across the voice box or larynx in such a way that it leaves a narrow slit between them for the passage of air. When we speak, air is forced into this small gap by the lungs which prompt vocal cords to vibrate. When the lungs force air through the slit, the vocal cords vibrate, producing sound.