Physiological Basis for Voice

Phonation refers to the process of using the vocal folds for the purpose of voicing speech. Many nonhuman animals use the vocal folds (also called vocal cords) to produce sound, but humans have taken this process to a much higher level. This entry examines the complex physiological basis for voice, focusing on the interaction between the airway and the vocal folds.

The vocal mechanism consists of the larynx, which sits atop the trachea. The larynx is actually a valve that closes off the airway to protect the lungs from foreign objects. The larynx provides a mechanism for completely closing off the airway through muscular effort, which can occur either through reflexive (e.g., coughing) or voluntary action. Voluntary closing of the larynx occurs in voicing for speech. ...