Illustration of a healthy larynx, also known as the voice box. At bottom is the hyoid bone (white, v-shaped), with the epiglottis (red) enclosed by it. The epiglottis is a flap that closes over the windpipe to prevent food from entering it. The vocal cords (upper frame) are responsible for the production of sound, and when brought close together they vibrate and emit sounds as air is expelled from the lungs.