In about ten percent of people, water—anything—touching the vocal cords triggers an immediate contraction in the muscles around the larynx. In effect, the central nervous system judges something in the voice box to be more of a threat than low oxygen levels in the blood, and acts accordingly. This is called a laryngospasm. It’s so powerful that it overcomes the breathing reflex and eventually suffocates the person. A person with laryngospasm drowns without any water in his lungs.
