Articulation (phonetics)

In phonetics and phonology, articulation is the movement of the tongue, lips, jaw, and other speech organs (the articulators) in order to make speech sounds.

Sound is produced simply by expelling air from the lungs. However, to vary the sound quality in a way that can be useful for speaking, two speech organs normally need to come close to each other to contact each other, so as to create an obstruction that shapes the air in a particular fashion. The point of maximum obstruction is known as the place of articulation, and the way in which the obstruction is formed and released is known as the manner of articulation. For example, when making a p sound, the two lips come together tightly, blocking the air for a little while and causing a buildup of air pressure. The lips are then released suddenly, leading to a burst of sound. The place of articulation of this sound is therefore called bilabial, and the manner is called stop (also known as a plosive).

Articulation can be shown with magnetic resonance imaging to demonstrate how the tongue, lips and jaw move and the rise and fall of the soft palate. Such movement alters resonant properties of the vocal tract, and imposes a "time-varying formant structure" onto the speech signal. The study of articulation in making speech is called articulatory phonetics.

An obstruction is necessarily formed when two articulators come close together. Generally, one is moving (the active articulator), and the other is stationary (the passive articulator). As a result, what is normally termed the "place of articulation" is actually a combination of a place of active articulation and a place of passive articulation. For example, the English f sound is said to be labiodental, which is a shorthand way of saying that the active articulator is the lower lip, which moves up (along with the jaw in general) to contact the upper teeth. The lower lip can also be the active articulator for other places of articulation (e.g. bilabial, where it contacts the upper lip, as in English p). Likewise, the upper teeth can be the passive articulator for other places of articulation (e.g. dental, where the tongue contacts the upper teeth, as in the English th sound).

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