In humans, the sounds is produced by the voice box or the larynx. Put your fingers on the throat and find a hard bump that seem to move when you swallow. This part of the body is known as the voice box. This is at the upper end of the wind pipe. Two vocal cords 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 the lungs force air through the suit the vocal cords vibrate, producing sound.