In articulatory phonetics, the place of articulation of a consonant is the point of contact where
an obstruction occurs in the vocal tract between an articulatory gesture, an active articulator,
and a passive location. Along with the manner of articulation and the phonation, this gives
the consonant its distinctive sound. The terminology in this article has been developed
to precisely describe all the consonants in all the world's spoken languages. No known
language distinguishes all of the places described here, so less precision is needed to distinguish
the sounds of a particular language.
Overview The human voice produces sounds in the following
manner: Air pressure from the lungs creates a steady
flow of air through the trachea, larynx and pharynx.
The vocal folds in the larynx vibrate, creating fluctuations in air pressure that are known
as sound waves. Resonances in the vocal tract modify these
waves according to the position and shape of the lips, jaw, tongue, soft palate, and
other speech organs, creating formant regions and thus different qualities of sonorant sound.
Mouth and nose openings radiate the sound waves into the environment.
The larynx
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.
This process continues in a periodic cycle that is felt as a vibration. 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. Place of articulation
The passive place of articulation is the place on the more stationary part of the vocal tract
where the articulation occurs. It can be anywhere from the lips, upper teeth, gums, or roof
of the mouth to the back of the throat. Although it is a continuum, there are several contrastive
areas such that languages may distinguish consonants by articulating them in different
areas, but few languages will contrast two sounds within the same area unless there is
some other feature which contrasts as well. The following areas are contrastive:
The upper lip The upper teeth, either on the edge of the
teeth or inner surface The alveolar ridge, the gum line just behind
the teeth The back of the alveolar ridge
The hard palate on the roof of the mouth The soft palate further back on the roof of
the mouth The uvula hanging down at the entrance to
the throat The throat itself, AKA the pharynx
The epiglottis at the entrance to the windpipe, above the voice box
These regions are not strictly separated. For instance, in many languages the surface
of the tongue contacts a relatively large area from the back of the upper teeth to the
alveolar ridge; this is common enough to have received its own name, denti-alveolar. Likewise,
the alveolar and post-alveolar regions merge into each other, as do the hard and soft palate,
the soft palate and the uvula, and indeed all adjacent regions. Terms like pre-velar,
post-velar, and upper vs lower pharyngeal may be used to specify more precisely where
an articulation takes place. However, although a language may contrast pre-velar and post-velar
sounds, it will not also contrast them with palatal and uvular sounds, so that contrasts
are limited to the number above if not always their exact location.
Place of articulation The articulatory gesture of the active place
of articulation involves the more mobile part of the vocal tract. This is typically some
part of the tongue or lips. The following areas are known to be contrastive:
The lower lip Various parts of the front of the tongue:
The tip of the tongue The upper front surface of the tongue just
behind the tip, called the blade of the tongue The surface of the tongue under the tip
The body of the tongue The base AKA root of the tongue in the throat
The epiglottis, the flap at the base of the tongue
The aryepiglottic folds at the entrance to the larynx
The glottis In bilabial consonants both lips move, so
the articulatory gesture is bringing together the lips, but by convention the lower lip
is said to be active and the upper lip passive. Similarly, in linguolabial consonants the
tongue contacts the upper lip with the upper lip actively moving down to meet the tongue;
nonetheless, in this gesture the tongue is conventionally said to be active and the lip
passive, if for no other reason than the fact that the parts of the mouth below the vocal
tract are typically active, and those above the vocal tract typically passive.
In dorsal gestures different parts of the body of the tongue contact different parts
of the roof of the mouth, but this cannot be independently controlled, so they are all
subsumed under the term dorsal. This is unlike coronal gestures involving the front of the
tongue, which is more flexible. The epiglottis may be active, contacting the
pharynx, or passive, being contacted by the aryepiglottal folds. Distinctions made in
these laryngeal areas are very difficult to observe and are the subject of ongoing investigation,
with several as-yet unidentified combinations thought possible.
The glottis acts upon itself. There is a sometimes fuzzy line between glottal, aryepiglottal,
and epiglottal consonants and phonation, which uses these same areas.
Unlike the passive articulation, which is a continuum, there are five discrete active
articulators: the lip, the flexible front of the tongue, the middle–back of the tongue,
the root of the tongue together with the epiglottis, and the larynx. These articulators are discrete
in that they can act independently of each other, and two or more may work together in
what is called coarticulation. The distinction between the various coronal articulations,
laminal, apical, and subapical, are however a continuum without clear boundaries.
Table of gestures and passive articulators and resulting places of articulation
The following table shows the possible combinations of active and passive articulators.
The possible locations where sibilants as well as non-sibilants can occur are indicated
in dashed red. For sibilants, there are additional complications involving tongue shape; see
the article on sibilants for a chart of possible articulations.
A precise vocabulary of compounding the two places of articulation is sometimes seen.
However, this is usually reduced to the passive articulation, which is generally sufficient.
Thus dorsal–palatal, dorsal–velar, and dorsal–uvular are usually just called "palatal",
"velar", and "uvular". Where there is ambiguity, additional terms have been invented, so subapical–palatal
is more commonly called "retroflex". NOTE: Additional shades of passive articulation
are sometimes specified using pre- or post-, for example prepalatal; or postvelar. These
can be useful in the precise description of sounds that are articulated somewhat farther
forward or back than a prototypical consonant; for this purpose, the "fronted" and "retracted"
IPA diacritics can be used. However, none of these additional shades are needed to phonemically
distinguish two consonants in a single language. Homorganic consonants
Consonants that have the same place of articulation, such as the alveolar sounds /n, t, d, s, z,
l/ in English, are said to be homorganic. Similarly, labial /p, b, m/ and velar /k,
ɡ, ŋ/ are homorganic. A homorganic nasal rule, an instance of assimilation, operates
in many languages, where a nasal consonant must be homorganic with a following stop.
We see this with English intolerable but implausible; another example is found in Yoruba, where
the present tense of ba "hide" is mba "is hiding", while the present of sun "sleep"
is nsun "is sleeping". Central and lateral articulation
The tongue contacts the mouth with a surface, which has two dimensions: length and width.
So far only points of articulation along its length have been considered. However, articulation
varies along its width as well. When the airstream is directed down the center of the tongue,
the consonant is said to be central. If, however, it is deflected off to one side, escaping
between the side of the tongue and the side teeth, it is said to be lateral. Nonetheless,
for simplicity's sake the place of articulation is assumed to be the point along the length
of the tongue, and the consonant may in addition be said to be central or lateral. That is,
a consonant may be lateral alveolar, like English , or lateral palatal, like Castilian
Spanish ll . Some Indigenous Australian languages contrast dental, alveolar, retroflex, and
palatal laterals, and many Native American languages have lateral fricatives and affricates
as well. Coarticulation
Some languages have consonants with two simultaneous places of articulation, called coarticulation.
When these are doubly articulated, the articulators must be independently movable, and therefore
there may only be one each from the major categories labial, coronal, dorsal, radical,
and laryngeal. The only common doubly articulated consonants
are labial–velar stops like [k͡p], [ɡ͡b], and less commonly [ŋ͡m], which are found
throughout West and Central Africa. Other combinations are rare. They include labial–(post)alveolar
stops [t͡p d͡b n͡m], found as distinct consonants only in a single language in New
Guinea, and a uvular–epiglottal stop, [q͡ʡ], found in Somali.
More commonly, coarticulation involves secondary articulation of an approximantic nature, in
which case both articulations can be similar, such as labialized labial [mʷ] or palatalized
velar [kʲ]. This is the case of English [w], which is a velar consonant with secondary
labial articulation. Common coarticulations include:
Labialization, rounding the lips while producing the obstruction, as in [kʷ] and English [w].
Palatalization, raising the body of the tongue toward the hard palate while producing the
obstruction, as in Russian [tʲ] and [ɕ]. Velarization, raising the back of the tongue
toward the soft palate, as in the English dark el, [lˠ].
Pharyngealization, constriction of the throat, such as Arabic "emphatic" [tˤ].
Production of vowels A vowel is any phoneme in which airflow is
impeded only or mostly by the voicing action of the vocal cords.
The well-defined fundamental frequency provided by the vocal cords in voiced phonemes is only
a convenience, however, not a necessity, since a strictly unvoiced whisper is still quite
intelligible. Our interest is therefore most focused on further modulations of and additions
to the fundamental tone by other parts of the vocal apparatus, determined by the variable
dimensions of oral, pharyngeal, and even nasal cavities.
Formants Formants are the resonant frequencies of the
vocal tract that emphasize particular voice harmonics near in frequency to the resonance,
or turbulent non-periodic energy near the formant frequency in the case of whispered
speech. The formants tell a listener what vowel is being spoken.
See also Manner of articulation
Relative articulation Tongue shape
Sibilant Index of phonetics articles
Notes
References Ladefoged, Peter; Maddieson, Ian. The Sounds
of the World's Languages. Oxford: Blackwell. ISBN 0-631-19814-8.
External links Interactive places and manners of articulation