ABSTRACT
When a human being speaks, the listener hears the product of both the voice and the speech articulators. Voice is made essentially by the vibration of the vocal folds (this is called ‘‘phonation’’). However, as we shall see, the sound that radiates out of the mouth is far more complex than this vibration because it is modified and resonated by the rest of the vocal tract to produce a recognizable voice quality. Furthermore, the articulatory structures of the vocal tract (including the lips, tongue, and soft palate) shape the sound source in an infinite number of combinations to make speech. This coordination of phonatory and articulatory behaviors represents arguably the most advanced sensori-motor system to be found in the human body (1).
