Which of the following is a type of functional voice disorder?

Muscle tension dysphonia is classified as a functional voice disorder because it primarily involves the misuse or overuse of the vocal mechanism rather than an anatomical or structural issue. This type of disorder is characterized by excessive tension in the muscles surrounding the larynx, which can lead to difficulty in voice production and discomfort.

While conditions like vocal fold paralysis, polyps, and vocal fold nodules may significantly affect voice quality, they are typically considered organic disorders. Organic disorders are associated with identifiable physical changes or structural abnormalities in the vocal folds or surrounding tissues. In contrast, muscle tension dysphonia does not stem from such abnormalities but rather from the way an individual is using their voice, often due to factors such as stress, improper vocal technique, or emotional states.

By understanding that muscle tension dysphonia is linked to functional aspects of voice use, it becomes clear why it is identified as a functional voice disorder, distinguishing it from the other choices presented.