The larynx (voice box) is an organ in the throat at the top of the trachea that prevents food from entering the trachea and houses the vocal folds (vocal cords). The muscles of the larynx control the shape of the larynx - particurly the vocal folds - to create sound. The sound made by the larynx is altered by the mouth, tongue, and lips to create the final sound of speech.
The larynx sits at the upper throat. It can be seen and felt by its most prominent feature - the Adam's apple. A larynx is usually around 2 inches long.
An infection of the larynx is called laryngitis.