Place of articulation

In articulatory phonetics, the place of articulation (also point of articulation) of a consonant is an approximate location along the vocal tract where its production occurs. It is a point where a constriction is made between an active and a passive articulator. Active articulators are organs capable of voluntary movement which create the constriction, while passive articulators are so called because they are normally fixed and are the parts with which an active articulator makes contact. Along with the manner of articulation and phonation, the place of articulation gives the consonant its distinctive sound.

Since vowels are produced with an open vocal tract, the point where their production occurs cannot be easily determined. Therefore, they are not described in terms of a place of articulation but by the relative positions in vowel space. This is mostly dependent on their formant frequencies and less on the specific tongue position and lip rounding.

The terminology used in describing places of articulation has been developed to allow specifying of all theoretically possible contrasts. No known language distinguishes all of the places described in the literature so less precision is needed to distinguish the sounds of a particular language.

The human voice produces sounds in the following manner:^{[page needed][page needed]}

The larynx or voice box is a cylindrical framework of cartilage that serves to anchor the vocal folds. When the muscles of the vocal folds contract, the airflow from the lungs is impeded until the vocal folds are forced apart again by the increasing air pressure from the lungs. The process continues in a periodic cycle that is felt as a vibration (buzzing). In singing, the vibration frequency of the vocal folds determines the pitch of the sound produced. Voiced phonemes such as the pure vowels are, by definition, distinguished by the buzzing sound of this periodic oscillation of the vocal cords.

The lips of the mouth can be used in a similar way to create a similar sound, as any toddler or trumpeter can demonstrate. A rubber balloon, inflated but not tied off and stretched tightly across the neck produces a squeak or buzz, depending on the tension across the neck and the level of pressure inside the balloon. Similar actions with similar results occur when the vocal cords are contracted or relaxed across the larynx.

The active articulators are movable parts of the vocal apparatus that impede or direct the airstream, typically some part of the tongue or lips. There are five major parts of the vocal tract that move: the lips, the flexible front of the tongue, the body of the tongue, the root of the tongue together with the epiglottis, and the glottis. They are discrete in that they can act independently of each other, and two or more may work together in what is called coarticulation.

The five main active parts can be further divided, as many languages contrast sounds produced within the same major part of the vocal apparatus. The following 9 degrees of active articulatory areas are known to be contrastive (sorted such that the top-most is in the front-most area of the mouth and the bottom-most is in the rear-most area of the mouth):