The larynx "houses" the vocal folds. There are three main structures of the larynx; the thyroid cartilage, hyoid bone and the cricoid cartilage. You can easily locate the thyroid cartilage (at the Adam's apple, which is larger in men). The vocal folds are protected by this cartilage, its Greek origin meaning "shield". Connected to the thyroid cartilage by a ligament and suspended above is the hyoid bone. This horse-shoe shaped bone is also attached to the base of the tongue. Below, attached to the thyroid cartilage is the ring-shaped cricoid cartilage. It is the uppermost ring of the trachea (airway). The larynx is structurally supported by the extrinsic muscles that connect the head, neck and clavicle.
Your voice begins by a regulated breath stream from the lungs that drives the vibration of the vocal folds. There are intrinsic muscles of the larynx that assist in vocal fold movement (opening, closing, lengthening shortening). The primary function of the larynx is to protect the airway from foreign objects (food, liquid) that could potentially infiltrate the lungs (aspiration). Therefore, there are more intrinsic muscles used in closing the vocal folds. Subsequent to this is voicing.
During sound production (exhalation) controlling the air stream is crucial for good sound and general vocal health. Too much breath pressure (pushing the breath) causes increased vocal fold resistance and is consequently the primary cause of vocal fold injury.
Sound is made upon exhalation of air on the undersurface of the vocal folds (which are closed). As the vocal folds are "blown open" by this increase in pressure, they are "sucked together" as pressure decreases (Bernoulli effect). Hence, vocal fold vibration.
The VOICE is the summation of all the subsystems or rather the "output" of the vocal tract and resonators.
