The human voice box, or larynx, allows us to breathe, speak, sing, and swallow without food entering the lungs. The larynx is composed of cartilage, muscle and connective tissues and is divided into 3 parts: the supraglottis, the glottis, and the subglottis. The supraglottis sits above the glottis and is especially important for airway protective functions. The subglottis sits below the glottis within the upper windpipe (aka trachea).
The glottis contains the vocal folds. The vocal folds have a unique structure that assists them in creating sounds through vibration. They are moved by muscles that attach within the larynx.