The vocal folds along with the larynx are responsible for the modulation of air and the production of sound while speaking. There exist a dual infolding of stretched mucous membrane in a horizontal manner along the larynx. True vocal cords (simply referred to as vocal cords) control the flow of air from the lungs during phonation (production of sound by the vocal cords through vibration).
True Vocal Cords: Vocal folds along with the larynx take care of the major sounds produced in humans through the oscillation of the dual folds. When these dual vocal folds are brought close to each other there would a build up of air pressure beneath the voice box.
- But, the development of pressure beneath the voice box, pushes the two folds away from each other causing an oscillation.
- When this oscillation of the two vocal folds sustains, the piled up pressure is released as sound (generated by the voice box) by breaking the air into steady sound waves.
Gender Differences in Vocal Cords: Men and women tend to have vocal folds of different sizes. It is this difference that causes the in the voice pitch.
- These folds are more whiter in color in women than in men.
- Also, adult males possess larger folds and lower pitch with the sizes varying between 17.5-25 mm (lengthwise).
- Female folds vary between the sizes 12.5-17.5 mm.
False Vocal Cords: These vocal folds exist at a slightly higher position to the true cords. They are also a pair of thick mucous membrane and are there to protect the true cords. The role they play in normal phonetics is minimal (true folds take care of this). But, for producing musical screaming and vocal styles such as death growl or deep sounds like in Tibetan chanting, these cords are useful.
- These folds are also known as ventricular or vestibular.
- Also, these folds can regenerate themselves upon surgical removal.
True vocal cords are very useful when it comes to our general phonetics while false ones are useful for the production of screams and deep voices. It is important not to place excess strain on these dual folds.
