The vocal folds (also called the vocal cords) are tiny, complex layered structures that sit in the neck behind the Adam’s apple. Their primary purpose is protection of the airway: The folds can move together across the airway (for example, during swallowing) to prevent foreign matter from entering the lungs. Because this function is quite basic biologically, the vocal folds are considered an evolutionarily “conservative” structure, and their anatomy and physiology is surprisingly similar across species.