Four main muscles are required for talking. These are the thyroarytenoid muscles, or vocalis muscles; the posterior cricoarytenoid muscles; the lateral cricoarytenoid muscle and the interarytenoid muscle.
Each of these muscles is integral to the creation of sound from the vocal cords. Each of the thyroarytenoid muscles is contained within a thin layer of mucosa, creating the vocal cord, or fold. The right and left cords are attached to the arytenoid cartilage. The posterior cricoarytenoid muscles are responsible for opening the vocal folds. The lateral cricoarytenoid muscle is responsible for closing the vocal cords. The interarytenoid muscle plays a stabilizing role by maintaining the stability of the arytenoids.