Laryngeal Anatomy 101
Singers don’t necessarily need to know how the voice works in order to sing, however a basic knowledge of vocal function and anatomy can be beneficial for the longevity of a voice and can assist in a healthy sound production. Knowledge of the larynx plays a key role in understanding the voice as it is the place where the vocal folds are attached to and ultimately the source of sound production.
The primary role of the larynx is of biological nature. It serves a protective role by preventing air from escaping the lungs, preventing foreign substances from entering the lungs, it assists in swallowing, and enables us to forcefully expel foreign substances (coughing, throat clearing).
Phonologically, the larynx is responsible for voice production, creating vocal fold vibration and enabling us to produce voiced and voiceless sounds.
Location and Cartilages:
The larynx is located at the upper end of the trachea and consists of three unpaired and three paired cartilages. The unpaired cartilages are the cricoid cartilage, the thyroid cartilage, also
referred to as the Adam’s apple and the Epiglottis which assists in swallowing. The paired cartilages are the Arytenoid cartilages which are the posterior (towards the back) point of attachment for the vocal folds, the corniculate cartilages and the cuneiform cartilages
The larynx holds intrinsic and extrinsic muscles. The names of the muscles are connected to the cartilages the muscle attaches to. The intrinsic muscles responsible for adduction (vocal fold closure) are the Cricoarytenoid and the Interarytenoids. The main muscle for abduction (opening of the vocal folds) is the Posterior Cricoarytenoid muscle. Vocal fold tension is primarily achieved by the Cricothyroid muscle (CT). The Thyrovocalis muscle (TA) stiffens the vocal folds and makes them shorter and fatter, this muscle also makes up the body of the vocal folds.
The extrinsic muscles can be divided into suprahyoid muscles, which attach above the hyoid bone and elevate the larynx; and infrahyoid muscles, which attach below the hyoid bone, and depress it.
Below is an image from the back.
Now that we have looked at the anatomical structure of the larynx, let’s take a look at the physiology of vocal fold vibration.
Vocal fold vibration is explained by the myoelastic-aerodynamic theory along with the Bernoulli principle. How does it work? First the adductor muscles (mentioned above) initiate vocal fold vibration (image 1). Once the subglottal pressure (the pressure that builds up beneath the vocal folds) reaches a threshold, the vocal folds are blown apart (image 3 and 4) until the elastic force of the tissue reaches a maximum (image 5). At this point the vocal folds start approximating again (image 6). As the air rushed through the narrow opening, it must accelerate to get through (image 7). This high speed air creates a suction effect and brings the vocal folds together (image 8, 9 and 10 – this is the Bernoulli effect). The vocal folds will continue this process many times per second, creating the pitch we perceive.
What does the larynx do when we sing?
The larynx position will affect your sound and is crucial if you want to sing in a healthy way. When you swallow you can feel your larynx moving up, when you yawn you can feel it lower down. When you sing, a balanced larynx position, not high and not low, is ideal. We usually use a balanced position when speaking. From there the larynx is free to move a little up and down. This movement is a natural thing. High notes ask for a little higher position than low notes. The Opera genre asks for a little lower position, Soul/Jazz/Pop are in a neutral larynx position and belted Musical Theater songs ask for a higher larynx position. However when a singer is straining or yelling, their larynx will most likely be in a raised position. A high larynx position should not be a default setting for singing as it can lead to vocal fatigue and tension and is not a healthy habit to enforce.
Balancing the larynx and finding the golden mean is the challenge and the reward 🙂
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