What do the vocal chords do?

Vocal folds (or cords), also known as vocal ligaments, are two elastic bands of tissue that vibrate in mammals to produce sound. Along with their role in sound generation, the vocal folds allow for the rapid opening and closing of the trachea (windpipe) at the top of the larynx, thus keeping the trachea closed during swallowing and coughing, and allowing air to pass into and out of the lungs under pressure for sound production.