Larynx, Vocal Cords, and Hoarseness

Normal Larynx

Larynx, also known as voice box, connects throat with trachea. Within the larynx lie vocal cords, which dictate your vocal tone or phonation. Larynx also works in sync with epiglottis to prevents food from going into your trachea and lungs.


Vocal tone results from the vibration of vocal cords as air comes out through them. An illustration of how vocal cords produce sound is as below.



The frequency of vibration determines the vocal pitch as heard by ears. The usual frequency during normal speech ranges from 100 to 300 times per second (Hz). Soprano singers' frequency can be greater than 1000 Hz. The above vocal pitch is probably not the best ear-pleasing sound you have ever heard. Many singers, however, are able to produce fantastic sound. An example of Sarah Brightman's soprano is as below.



Hoarseness refers to any change in voice that indicates injuries to larynx or vocal cords. These injuries may be due to inflammation, infection, tumor, or neurological diseases.

If you smoke cigarettes or drink excess alcohol, your hoarseness usually indicates the inflammation of larynx, also known as laryngitis. Hoarseness that lasts for more than 2 weeks, however, requires a complete examination to rule out laryngeal cancer.