Ironically, the voice box (larynx) is not actually designed for speech. Humans have learned to use it for speech, but that really isn't its primary function; rather, it is there to separate the food tube from the breathing tube. However, for anyone with a voice or speech disorder, that primary function is of secondary importance.
The voice box consists of cartilage, muscle, the epiglottis (which helps protect the voice box during swallowing) and the vocal folds (vocal cords). Muscles control the movement of the vocal folds, which open to allow breathing and close to allow speech. Problems can occur anywhere within this area, leading to a variety of symptoms, diagnoses and treatments.
Voice Patient Questionnaire (for initial consultation)