The larynx, or voicebox, is made up of cartilage, muscle, and ligaments that function together to provide airway protection and a sound source. The main cartilage is called the thyroid cartilage, also known as the “Adam’s apple”.
It is suspended within the neck from a complex of ligaments and muscles that allow the voicebox to move up and down as well as left and right. Within the thyroid cartilage, there are two sets of muscles that close the vocal folds and two sets that tense the vocal folds much like a guitar string. However, there is only one set of muscles that open the vocal folds.
The function of the larynx is one of the most complex in the human body. The vocal folds have often been described as a valve. They open widely when breathing to allow for easy passage of air into the windpipe and lungs. Conversely, they close when eating to protect the airway from misdirected food or liquids. The vocal folds also close and vibrate when talking or singing. During sound production a column of air is pushed upwards from the windpipe through the closed vocal folds, which entrains oscillation or vibration and ultimate sound production.
This is perhaps the most interesting function as it provides our ability to communicate. Consider everyday communications between your family, friends, and coworkers. It is difficult to get through a day without talking to at least one individual. It is how we, as humans, share thoughts and emotions. In some cases, the quality of our voice is our signature.
At a high level, performers and professional voice users finely control the sounds produced by the vocal folds to create beautiful, sonorous music or engaging presentations.
Imagine your favorite musician or speaker, and how their voice – and, more importantly, the control of their voice – defines your impression and enjoyment of their art or presentation. It is for these reasons that a properly functioning voicebox is critical.