Vocal cords

The vocal folds or vocal cords are mucous membranes over the larynx that contribute to the production of sound in human articulation. The folds can vibrate as air is drawn up from the lungs, allowing distinctions in phonetics and phonology such as the difference between [b] and [p]; this is called voicing, and the folds plus the space between them are known as the glottis. When closed, the blockage of air can lead to the production of a glottal stop; other degrees of closure allow 'breathy voice' or 'creaky voice', which allows for further phonemic distinctions in many languages.