Articulation (speech)

''' In linguistics (articulatory phonetics), manner of articulation describes how the tongue, lips, and other speech organs are involved in making a sound make contact. Often the concept is only used for the production of consonants. For any place of articulation, there may be several manners, and therefore several homorganic consonants.

One parameter of manner is stricture, that is, how closely the speech organs approach one another. Parameters other than stricture are those involved in the ar sounds (taps and trills), and the sibilancy of fricatives. Often nasality and laterality are included in manner, but phoneticians such as Peter Ladefoged consider them to be independent.

Stricture
From greatest to least stricture, speech sounds may be classified along a cline as stop consonants (with occlusion, or blocked airflow), fricative consonants (with partially blocked and therefore strongly turbulent airflow), approximants (with only slight turbulence), and vowels (with full unimpeded airflow). Affricates often behave as if they were intermediate between stops and fricatives, but phonetically they are sequences of stop plus fricative.

Historically, sounds may move along this cline toward less stricture in a process called lenition.

Other parameters
Sibilants are distinguished from other fricatives by the shape of the tongue and how the airflow is directed over the teeth. Fricatives at coronal places of articulation may be sibilant or non-sibilant, sibilants being the more common.

Taps and flaps are similar to very brief stops. However, their articulation and behavior is distinct enough to be considered a separate manner, rather than just length.

Trills involve the vibration of one of the speech organs. Since trilling is a separate parameter from stricture, the two may be combined. Increasing the stricture of a typical trill results in a trilled fricative. Trilled affricates are also known.

Nasal airflow may be added as an independent parameter to any speech sound. It is most commonly found in nasal stops and nasal vowels, but nasal fricatives, taps, and approximants are also found. When a sound is not nasal, it is called oral. An oral stop is often called a plosive, while a nasal stop is generally just called a nasal.

Laterality is the release of airflow at the side of the tongue. This can also be combined with other manners, resulting in lateral approximants (the most common), lateral flaps, and lateral fricatives and affricates.

Individual manners

 * Plosive, or oral stop, where there is complete occlusion (blockage) of both the oral and nasal cavities of the vocal tract, and therefore no air flow. Examples include English /p t k/ (voiceless) and /b d g/ (voiced). If the consonant is voiced, the voicing is the only sound made during occlusion; if it is voiceless, a plosive is completely silent. What we hear as a /p/ or /k/ is the effect that the onset of the occlusion has on the preceding vowel, and well as the release burst and its effect on the following vowel. The shape and position of the tongue (the place of articulation) determine the resonant cavity that gives different plosives their characteristic sounds. All languages have plosives.


 * Nasal stop, usually shortened to nasal, where there is complete occlusion of the oral cavity, and the air passes instead through the nose. The shape and position of the tongue determine the resonant cavity that gives different nasal stops their characteristic sounds. Examples include English /m, n/. Nearly all languages have nasals, the only exceptions being in the area of Puget Sound and a single language on Bougainville Island.


 * Fricative, sometimes called spirant, where there is continuous frication (turbulent and noisy airflow) at the place of articulation. Examples include English /f, s/ (voiceless), /v, z/ (voiced), etc. Most languages have fricatives, though many have only an /s/. However, the Australian languages are almost completely devoid of fricatives of any kind.


 * Sibilants are a type of fricative where the airflow is guided by a groove in the tongue toward the teeth, creating a high-pitched and very distinctive sound. These are by far the most common fricatives. Fricatives at coronal (front of tongue) places of articulation are usually, though not always, sibilants. English sibilants include /s/ and /z/.


 * Lateral fricatives are a rare type of fricative, where the frication occurs on one or both sides of the edge of the tongue. The "ll" of the Welsh language and the "hl" of Zulu are lateral fricatives.


 * Affricate, which begins like a plosive, but this releases into a fricative rather than having a separate release of its own. The English letters "ch" and "j" represent affricates. Affricates are quite common around the world, though less common than fricatives.


 * Flap, often called a tap, is a momentary closure of the oral cavity. The "tt" of "utter" and the "dd" of "udder" are pronounced as a flap in North American English. Many linguists distinguish taps from flaps, but there is no consensus on what the difference might be. No language relies on such a difference. There are also lateral flaps.


 * Trill, in which the articulator (usually the tip of the tongue) is held in place, and the airstream causes it to vibrate. The double "r" of Spanish "perro" is a trill. Trills and flaps, where there are one or more brief occlusions, constitute a class of consonant called rhotics.


 * Approximant, where there is very little obstruction. Examples include English /w/ and /r/. In some languages, such as Spanish, there are sounds which seem to fall between fricative and approximant.


 * One use of the word semivowel is a type of approximant, pronounced like a vowel but with the tongue closer to the roof of the mouth, so that there is slight turbulence. In English, /w/ is the semivowel equivalent of the vowel /u/, and /j/ (spelled "y") is the semivowel equivalent of the vowel /i/ in this usage. Other descriptions use semivowel for vowel-like sounds that are not syllabic, but do not have the increased stricture of approximants. These are found as elements in diphthongs. The word may also be used to cover both concepts.


 * Lateral approximants, usually shortened to lateral, are a type of approximant pronounced with the side of the tongue. English /l/ is a lateral. Together with the rhotics, which have similar behavior in many languages, these form a class of consonant called liquids.

Broader classifications
Manners of articulation with substantial obstruction of the airflow (plosives, fricatives, affricates) are called obstruents. These are prototypically voiceless, but voiced obstruents are extremely common as well. Manners without such obstruction (nasals, liquids, approximants, and also vowels) are called sonorants because they are nearly always voiced. Voiceless sonorants are uncommon, but are found in Welsh and Classical Greek (the spelling "rh"), in Tibetan (the "lh" of Lhasa), and the "wh" in those dialects of English which distinguish "which" from "witch".

Sonorants may also be called resonants, and some linguists prefer that term, restricting the word 'sonorant' to non-vocoid resonants (that is, nasals and liquids, but not vowels or semi-vowels). Another common distinction is between stops (plosives and nasals) and continuants (all else); affricates are considered to be both, because they are sequences of stop plus fricative.

Other airstream initiations
All of these manners of articulation are pronounced with an airstream mechanism called pulmonic egressive, meaning that the air flows outward, and is powered by the lungs (actually the ribs and diaphragm). Other airstream mechanisms are possible. Sounds which rely on some of these include:


 * Ejectives, which are glottalic egressive. That is, the airstream is powered by an upward movement of the glottis rather than by the lungs or diaphragm. Plosives, affricates, and occasionally fricatives may occur as ejectives. All ejectives are voiceless.


 * Implosives, which are glottalic ingressive. Here the glottis moves downward, but the lungs may be used simultaneously (to provide voicing), and in some languages no air may actually flow into the mouth. Implosive oral stops are not uncommon, but implosive affricates and fricatives are rare. Voiceless implosives are also rare.


 * Clicks, which are velaric ingressive. Here the back of the tongue is used to create a vacuum in the mouth, causing air to rush in when the forward occlusion (tongue or lips) is released. Clicks may be oral or nasal, stop or affricate, central or lateral, voiced or voiceless. They are extremely rare in normal words outside Southern Africa. However, English has a click in its "tsk tsk" (or "tut tut") sound, and another is used to say "giddy up" to a horse.