Most people are familiar with membranes in the throat that allow the human body to make noise called the vocal cords. Many may not realize the prominence or even the existence of two membranes located near the body's voice boxes, however. False vocal cords — also known as vestibular cords or superior vocal cords — differentiate from true vocal cords in a couple of important ways. True vocal cords are used primarily in voice production, and the general inability of vestibular cords to produce the sounds associated with speech is what gives these structures the distinction of "false." True vocal cords are also made of more delicate epithelial tissue, which helps give them their vibrating capacity. The tissue of false vocal cords is thicker and, unlike true vocal cords, can actually regenerate when removed.
A false vocal cord has a simple composition. Layers of tissue called mucous membranes fold to form the basic material of the false vocal cord. Connective tissues known as thyroid and arytenoid cartilage help the cords with movement, and the true vocal cords and false vocal cords collectively are known as thyroarytenoid muscles. False vocal cords form the upper, superior portion of these muscles, and thus they are part of the supraglottic larynx. This portion of the larynx, although sturdier, is more susceptible to disease: supraglottic tumors make up nearly one-third of all laryngeal cancers.
The cords surround connective tissue called the ventricular ligament. This ligament connects to portions of the larynx and thus to the tissues in the mouth that regulate swallowing called the epiglottis. False vocal cords help protect these tissues. The false vocal cord, in turn, helps protect one’s swallowing capacity by refusing a foreign object's entrance. One’s voice is protected as well because false vocal cords help lubricate the true vocal cords, and they also contain immune response cells that shield the vocal tract from infectious bacteria or fungi.
Although false vocal cords are used rarely in regular speech, their highest value in sound production arises from their ability to produce deep tones, such as screaming and growling. The false vocal cord serves as the centerpiece of many alternative and creative vocal pursuits, such as throat singing, Tibetan chanting, and death growl vocals. These deep, guttural sounds are produced when the false vocal cords press together and muffle the true vocal cords. Practitioners generally achieve this result by filling the lungs with air and pushing it out in such a way that tightens the throat. Overuse of this technique, however, can lead to a disorder known as hyperfunctional voice disorder.