How is speech normally produced?

Speech is normally produced through a series of precisely coordinated muscle movements involving respiration (the breathing mechanism), phonation (the voicing mechanism) and articulation (throat, palate, tongue, lips and teeth). These muscle movements are initiated, coordinated and controlled by the brain and monitored through the senses of hearing and touch.

Before speaking, an individual takes a breath and the vocal folds (or vocal cords), which are two bands of muscular tissue located in the voice box directly above the trachea or windpipe, must come together. The air that is held in the lungs is gradually released, passing through the gently closed vocal folds thus causing vibration and producing the voice. The sound of the voice is passed through the throat and is directed into the mouth for most speech sounds, or into the nose for nasal sounds such as "m," "n" and "ng." The palate, tongue, jaw and lips move in precise ways to modify the sounds in order to make speech sounds.