What is the main role of the Thyroarytenoid muscle?

The main role of the Thyroarytenoid muscle is to decrease the pitch by relaxing the vocal cords. This muscle is located within the larynx and is a key component of the vocal fold structure. When the Thyroarytenoid muscle contracts, it shortens and thickens the vocal folds. This action lowers the tension of the vocal cords, resulting in a deeper pitch when producing sound.

As the vocal folds relax and become less tense, the frequency of the vibrations decreases, which corresponds to a lower pitch. This mechanism is essential in the control of voice pitch during speech and singing. When the muscle is relaxed, the vocal cords have more mass and less tension, allowing them to vibrate at lower frequencies.

Other muscles in the larynx, such as the cricothyroid muscle, counteract this action by lengthening and tensing the vocal cords to increase pitch, showcasing the collaborative role of various muscles in pitch modulation. Hence, the Thyroarytenoid muscle's primary function in vocal production is to adjust the pitch to lower frequencies through relaxation of the vocal cords.