Vocal flexibility is dependent on the responsiveness of two key components in the vocal mechanism. First is the thyroarytenoid muscles, located inside the larynx. They play a pivotal role in positioning and relaxing the vocal folds in order to remain responsive and elastic. Second, is the vocal folds, made up of five layers: (1) Vocalis – innermost layer, which stiffens the folds, and adjusts their length, mass, and position. (2-4) Lamina Propria – These layers store water in the form of hyaluronic acid, keeping the folds lubricated, and they collectively vibrate against the airflow coming up from the lungs, creating different frequencies and qualities of sound. Sometimes referred to as a single layer, they can be broken down into three: the deep, the intermediate, and the superficial. These layers collectively vibrate against the airflow coming up from the lungs, creating different frequencies and qualities of sound, which also store water in the form of hyaluronic acid, keeping the folds lubricated. (5) Epithelium – thin, outermost layer, protecting the more sensitive layers underneath and also providing a smooth surface for air to vibrate against.
The Importance of Water: The three middle (LP) layers are essential to the functionality of the vocal folds and their ability to vibrate. Keeping them hydrated will prevent friction and heat, which cause them to swell and stiffen. A lack of hydration can cause the voice to fatigue quickly and/or become hoarse.
