The field of articulatory phonetics is a subfield of
phonetics
Phonetics is a branch of linguistics that studies how humans produce and perceive sounds, or in the case of sign languages, the equivalent aspects of sign. Linguists who specialize in studying the physical properties of speech are phoneticians. ...
that studies articulation and ways that humans produce speech. Articulatory phoneticians explain how humans produce speech
sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' b ...
s via the interaction of different
physiological structures. Generally, articulatory phonetics is concerned with the transformation of
aerodynamic
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
into
acoustic energy. Aerodynamic energy refers to the airflow through the
vocal tract. Its
potential
Potential generally refers to a currently unrealized ability. The term is used in a wide variety of fields, from physics to the social sciences to indicate things that are in a state where they are able to change in ways ranging from the simple r ...
form is
air pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars ...
; its
kinetic form is the actual
dynamic airflow. Acoustic energy is variation in the air pressure that can be represented as
sound waves, which are then perceived by the human
auditory system as sound.
Respiratory sounds
Respiratory sounds, also known as lung sounds or breath sounds, refer to the specific sounds generated by the movement of air through the respiratory system. These may be easily audible or identified through auscultation of the respiratory system ...
can be produced by expelling air from the lungs. However, to vary the sound quality in a way useful for speaking, two speech organs normally move towards each other to contact each other to create an obstruction that shapes the air in a particular fashion. The point of maximum obstruction is called the ''
place of articulation
In articulatory phonetics, the place of articulation (also point of articulation) of a consonant is a location along the vocal tract where its production occurs. It is a point where a constriction is made between an active and a passive articula ...
'', and the way the obstruction forms and releases is the ''
manner of articulation''. For example, when making a ''p'' sound, the lips come together tightly, blocking the air momentarily and causing a buildup of
air pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars ...
. The lips then release suddenly, causing a burst of sound. The place of articulation of this sound is therefore called ', and the manner is called ' (also known as a ''
plosive'').
Components
The vocal tract can be viewed through an aerodynamic-
biomechanic
Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to organs, cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of ...
model that includes three main components:
# air cavities
# pistons
# air valves
Air
cavities are containers of air
molecule
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
s of specific
volume
Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...
s and
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different eleme ...
es. The main air cavities present in the articulatory system are the supraglottal cavity and the subglottal cavity. They are so-named because the
glottis, the openable space between the
vocal folds
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speec ...
internal to the
larynx, separates the two cavities. The supraglottal cavity or the orinasal cavity is divided into an
oral subcavity (the cavity from the glottis to the
lip
The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...
s excluding the nasal cavity) and a
nasal subcavity (the cavity from the velopharyngeal port, which can be closed by raising the
velum). The subglottal cavity consists of the
trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from the ...
and the
lungs. The
atmosphere external to the articulatory stem may also be considered an air cavity whose potential connecting points with respect to the body are the nostrils and the lips.
Pistons are initiators. The term ''initiator'' refers to the fact that they are used to initiate a change in the volumes of air cavities, and, by
Boyle's Law
Boyle's law, also referred to as the Boyle–Mariotte law, or Mariotte's law (especially in France), is an experimental gas law that describes the relationship between pressure and volume of a confined gas. Boyle's law has been stated as:
The ...
, the corresponding air
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...
of the cavity. The term ''initiation'' refers to the change. Since changes in air pressures between connected cavities lead to airflow between the cavities, initiation is also referred to as an ''
airstream mechanism
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for sound pr ...
''. The three pistons present in the articulatory system are the larynx, the
tongue
The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by taste ...
body, and the physiological structures used to manipulate lung volume (in particular, the floor and the walls of the
chest
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...
). The lung pistons are used to initiate a
pulmonic airstream (found in all human languages). The larynx is used to initiate the
glottalic airstream mechanism by changing the volume of the supraglottal and subglottal cavities via vertical movement of the larynx (with a closed glottis).
Ejective
In phonetics, ejective consonants are usually voiceless consonants that are pronounced with a glottalic egressive airstream. In the phonology of a particular language, ejectives may contrast with aspirated, voiced and tenuis consonants. Some ...
s and
implosive
Implosive consonants are a group of stop consonants (and possibly also some affricates) with a mixed glottalic ingressive and pulmonic egressive airstream mechanism.''Phonetics for communication disorders.'' Martin J. Ball and Nicole Müller. Ro ...
s are made with this airstream mechanism. The tongue body creates a velaric airstream by changing the pressure within the oral cavity: the tongue body changes the mouth subcavity.
Click consonants use the velaric airstream mechanism. Pistons are controlled by various
muscles.
Valve
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...
s regulate airflow between cavities. Airflow occurs when an air valve is open and there is a pressure difference between the connecting cavities. When an air valve is closed, there is no airflow. The air valves are the vocal folds (the glottis), which regulate between the supraglottal and subglottal cavities, the velopharyngeal port, which regulates between the oral and nasal cavities, the tongue, which regulates between the oral cavity and the atmosphere, and the lips, which also regulate between the oral cavity and the atmosphere. Like the pistons, the air valves are also controlled by various muscles.
Initiation
To produce any kind of sound, there must be movement of air. To produce sounds that people can interpret as spoken words, the movement of air must pass through the vocal cords, up through the throat and, into the mouth or nose to then leave the body. Different sounds are formed by different positions of the mouth—or, as linguists call it, "the oral cavity" (to distinguish it from the nasal cavity).
Consonants
Consonants are speech sounds that are articulated with a complete or partial closure of the
vocal tract. They are generally produced by the modification of an
airstream exhaled from the lungs. The respiratory organs used to create and modify airflow are divided into three regions: the vocal tract (supralaryngeal), the
larynx, and the subglottal system. The airstream can be either
egressive (out of the vocal tract) or
ingressive
In phonetics, ingressive sounds are sounds by which the airstream flows inward through the mouth or nose. The three types of ingressive sounds are lingual ingressive or velaric ingressive (from the tongue and the velum), glottalic ingressive (f ...
(into the vocal tract). In pulmonic sounds, the airstream is produced by the lungs in the subglottal system and passes through the larynx and vocal tract.
Glottalic sounds use an airstream created by movements of the larynx without airflow from the lungs.
Click consonants are articulated through the
rarefaction of air using the tongue, followed by releasing the forward closure of the tongue.
Place of articulation
Consonants are pronounced in the vocal tract, usually in the mouth. In order to describe the place of articulation, the
active and passive articulator need to be known. In most cases, the active articulators are the lips and tongue. The passive articulator is the surface on which the constriction is created. Constrictions made by the lips are called
labials. Constrictions can be made in several parts of the vocal tract, broadly classified into coronal, dorsal and radical places of articulation.
Coronal articulations are made with the front of the tongue,
dorsal
Dorsal (from Latin ''dorsum'' ‘back’) may refer to:
* Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism
* Dorsal, positioned on top of an aircraft's fuselage
* Dorsal c ...
articulations are made with the back of the tongue, and
radical articulations are made in the
pharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...
. These divisions are not sufficient for distinguishing and describing all speech sounds. For example, in English the sounds and are both coronal, but they are produced in different places of the mouth. To account for this, more detailed places of articulation are needed based upon the area of the mouth in which the constriction occurs.
Labial consonants
Articulations involving the lips can be made in three different ways: with both lips (bilabial), with one lip and the teeth (labiodental), and with the tongue and the upper lip (linguolabial). Depending on the definition used, some or all of these kinds of articulations may be categorized into the class of
labial articulations. Ladefoged and Maddieson (1996) propose that linguolabial articulations be considered coronals rather than labials, but make clear this grouping, like all groupings of articulations, is equivocal and not cleanly divided. Linguolabials are included in this section as labials given their use of the lips as a place of articulation.
Bilabial consonants are made with both lips. In producing these sounds the lower lip moves farthest to meet the upper lip, which also moves down slightly, though in some cases the force from air moving through the aperture (opening between the lips) may cause the lips to separate faster than they can come together. Unlike most other articulations, both articulators are made from soft tissue, and so bilabial stops are more likely to be produced with incomplete closures than articulations involving hard surfaces like the teeth or palate. Bilabial stops are also unusual in that an articulator in the upper section of the vocal tract actively moves downwards, as the upper lip shows some active downward movement.
Labiodental consonants are made by the lower lip rising to the upper teeth. Labiodental consonants are most often
fricative
A fricative is a consonant produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate in t ...
s while labiodental nasals are also typologically common. There is debate as to whether true labiodental
plosives occur in any natural language, though a number of languages are reported to have labiodental plosives including
Zulu,
Tonga
Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...
, and
Shubi. Labiodental
affricates are reported in
Tsonga which would require the stop portion of the affricate to be a labiodental stop, though Ladefoged and Maddieson (1996) raise the possibility that labiodental affricates involve a bilabial closure like "pf" in German. Unlike plosives and affricates, labiodental nasals are common across languages.
Linguolabial consonants are made with the blade of the tongue approaching or contacting the upper lip. Like in bilabial articulations, the upper lip moves slightly towards the more active articulator. Articulations in this group do not have their own symbols in the International Phonetic Alphabet, rather, they are formed by combining an apical symbol with a diacritic implicitly placing them in the coronal category. They exist in a number of languages indigenous to
Vanuatu
Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
such as
Tangoa, though early descriptions referred to them as apical-labial consonants. The name "linguolabial" was suggested by
Floyd Lounsbury given that they are produced with the blade rather than the tip of the tongue.
Coronal consonants
Coronal consonants are made with the tip or blade of the tongue and, because of the agility of the front of the tongue, represent a variety not only in place but in the posture of the tongue. The coronal places of articulation represent the areas of the mouth where the tongue contacts or makes a constriction, and include dental, alveolar, and post-alveolar locations. Tongue postures using the tip of the tongue can be
apical
Apical means "pertaining to an apex". It may refer to:
*Apical ancestor, refers to the last common ancestor of an entire group, such as a species (biology) or a clan (anthropology)
*Apical (anatomy), an anatomical term of location for features loc ...
if using the top of the tongue tip,
laminal if made with the blade of the tongue, or
sub-apical if the tongue tip is curled back and the bottom of the tongue is used. Coronals are unique as a group in that every
manner of articulation is attested.
Australian languages are well known for the large number of coronal contrasts exhibited within and across languages in the region.
Dental consonant
A dental consonant is a consonant articulated with the tongue against the upper teeth, such as , . In some languages, dentals are distinguished from other groups, such as alveolar consonants, in which the tongue contacts the gum ridge. Dental c ...
s are made with the tip or blade of the tongue and the upper teeth. They are divided into two groups based upon the part of the tongue used to produce them: apical dental consonants are produced with the tongue tip touching the teeth; interdental consonants are produced with the blade of the tongue as the tip of the tongue sticks out in front of the teeth. No language is known to use both contrastively though they may exist
allophonically.
Alveolar consonant
Alveolar (; UK also ) consonants are articulated with the tongue against or close to the superior alveolar ridge, which is called that because it contains the alveoli (the sockets) of the upper teeth. Alveolar consonants may be articulated wit ...
s are made with the tip or blade of the tongue at the alveolar ridge just behind the teeth and can similarly be apical or laminal.
Crosslinguistically, dental consonants and alveolar consonants are frequently contrasted leading to a number of generalizations of crosslinguistic patterns. The different places of articulation tend to also be contrasted in the part of the tongue used to produce them: most languages with dental stops have laminal dentals, while languages with alveolar stops usually have apical stops. Languages rarely have two consonants in the same place with a contrast in laminality, though
Taa (ǃXóõ) is a counterexample to this pattern. If a language has only one of a dental stop or an alveolar stop, it will usually be laminal if it is a dental stop, and the stop will usually be apical if it is an alveolar stop, though for example
Temne and
Bulgarian do not follow this pattern. If a language has both an apical and laminal stop, then the laminal stop is more likely to be affricated like in
Isoko, though
Dahalo show the opposite pattern with alveolar stops being more affricated.
Retroflex consonant
A retroflex ( /ˈɹɛtʃɹoːflɛks/), apico-domal ( /əpɪkoːˈdɔmɪnəl/), or cacuminal () consonant is a coronal consonant where the tongue has a flat, concave, or even curled shape, and is articulated between the alveolar ridge and the h ...
s have several different definitions depending on whether the position of the tongue or the position on the roof of the mouth is given prominence. In general, they represent a group of articulations in which the tip of the tongue is curled upwards to some degree. In this way, retroflex articulations can occur in several different locations on the roof of the mouth including alveolar, post-alveolar, and palatal regions. If the underside of the tongue tip makes contact with the roof of the mouth, it is sub-apical though apical post-alveolar sounds are also described as retroflex. Typical examples of sub-apical retroflex stops are commonly found in
Dravidian languages
The Dravidian languages (or sometimes Dravidic) are a family of languages spoken by 250 million people, mainly in southern India, north-east Sri Lanka, and south-west Pakistan. Since the colonial era, there have been small but significant ...
, and in some
languages indigenous to the southwest United States the contrastive difference between dental and alveolar stops is a slight retroflexion of the alveolar stop. Acoustically, retroflexion tends to affect the higher formants.
Articulations taking place just behind the alveolar ridge, known as
post-alveolar consonant
Postalveolar or post-alveolar consonants are consonants articulated with the tongue near or touching the ''back'' of the alveolar ridge. Articulation is farther back in the mouth than the alveolar consonants, which are at the ridge itself, but n ...
s, have been referred to using a number of different terms. Apical post-alveolar consonants are often called retroflex, while laminal articulations are sometimes called palato-alveolar; in the Australianist literature, these laminal stops are often described as 'palatal' though they are produced further forward than the palate region typically described as palatal. Because of individual anatomical variation, the precise articulation of palato-alveolar stops (and coronals in general) can vary widely within a speech community.
Dorsal consonants
Dorsal consonants are those consonants made using the tongue body rather than the tip or blade.
Palatal consonants are made using the tongue body against the hard palate on the roof of the mouth. They are frequently contrasted with velar or uvular consonants, though it is rare for a language to contrast all three simultaneously, with
Jaqaru as a possible example of a three-way contrast.
Velar consonants are made using the tongue body against the
velum. They are incredibly common cross-linguistically; almost all languages have a velar stop. Because both velars and vowels are made using the tongue body, they are highly affected by
coarticulation Coarticulation in its general sense refers to a situation in which a conceptually isolated speech sound is influenced by, and becomes more like, a preceding or following speech sound. There are two types of coarticulation: ''anticipatory coarticulat ...
with vowels and can be produced as far forward as the hard palate or as far back as the uvula. These variations are typically divided into front, central, and back velars in parallel with the vowel space. They can be hard to distinguish phonetically from palatal consonants, though are produced slightly behind the area of prototypical palatal consonants.
Uvular consonants
Uvulars are consonants articulated with the back of the tongue against or near the uvula, that is, further back in the mouth than velar consonants. Uvulars may be stops, fricatives, nasals, trills, or approximants, though the IPA does not prov ...
are made by the tongue body contacting or approaching the uvula. They are rare, occurring in an estimated 19 percent of languages, and large regions of the Americas and Africa have no languages with uvular consonants. In languages with uvular consonants, stops are most frequent followed by
continuants (including nasals).
Radical consonants
Radical consonants either use the root of the tongue or the
epiglottis
The epiglottis is a leaf-shaped flap in the throat that prevents food and water from entering the trachea and the lungs. It stays open during breathing, allowing air into the larynx. During swallowing, it closes to prevent aspiration of food in ...
during production.
Pharyngeal consonants are made by retracting the root of the tongue far enough to touch the wall of the
pharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...
. Due to production difficulties, only fricatives and approximants can produced this way.
Epiglottal consonant
A pharyngeal consonant is a consonant that is articulated primarily in the pharynx. Some phoneticians distinguish upper pharyngeal consonants, or "high" pharyngeals, pronounced by retracting the root of the tongue in the mid to upper pharynx, ...
s are made with the epiglottis and the back wall of the pharynx. Epiglottal stops have been recorded in
Dahalo. Voiced epiglottal consonants are not deemed possible due to the cavity between the
glottis and epiglottis being too small to permit voicing.
Glottal consonants
Glottal consonants are those produced using the vocal folds in the larynx. Because the vocal folds are the source of phonation and below the oro-nasal vocal tract, a number of glottal consonants are impossible such as a voiced glottal stop. Three glottal consonants are possible, a voiceless glottal stop and two glottal fricatives, and all are attested in natural languages.
Glottal stops, produced by closing the
vocal folds
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speec ...
, are notably common in the world's languages. While many languages use them to demarcate phrase boundaries, some languages like
Huatla Mazatec have them as contrastive phonemes. Additionally, glottal stops can be realized as
laryngealization of the following vowel in this language. Glottal stops, especially between vowels, do usually not form a complete closure. True glottal stops normally occur only when they're
geminated.
Manner of articulation
Knowing the place of articulation is not enough to fully describe a consonant, the way in which the stricture happens is equally important. Manners of articulation describe how exactly the active articulator modifies, narrows or closes off the vocal tract.
Stops (also referred to as plosives) are consonants where the airstream is completely obstructed. Pressure builds up in the mouth during the stricture, which is then released as a small burst of sound when the articulators move apart. The velum is raised so that air cannot flow through the nasal cavity. If the velum is lowered and allows for air to flow through the nose, the result in a nasal stop. However, phoneticians almost always refer to nasal stops as just "nasals".
Affricates are a sequence of stops followed by a fricative in the same place.
Fricatives
A fricative is a consonant produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of ; the back of the tongue against the soft palate in t ...
are consonants where the airstream is made turbulent by partially, but not completely, obstructing part of the vocal tract.
Sibilants are a special type of fricative where the turbulent airstream is directed towards the teeth, creating a high-pitched hissing sound.
Nasals
In phonetics, a nasal, also called a nasal occlusive or nasal stop in contrast with an oral stop or nasalized consonant, is an occlusive consonant produced with a lowered velum, allowing air to escape freely through the nose. The vast majorit ...
(sometimes referred to as nasal stops) are consonants in which there's a closure in the oral cavity and the velum is lowered, allowing air to flow through the nose.
In an
approximant, the articulators come close together, but not to such an extent that allows a turbulent airstream.
Laterals are consonants in which the airstream is obstructed along the center of the vocal tract, allowing the airstream to flow freely on one or both sides. Laterals have also been defined as consonants in which the tongue is contracted in such a way that the airstream is greater around the sides than over the center of the tongue. The first definition does not allow for air to flow over the tongue.
Trills are consonants in which the tongue or lips are set in motion by the airstream. The stricture is formed in such a way that the airstream causes a repeating pattern of opening and closing of the soft articulator(s). Apical trills typically consist of two or three periods of vibration.
Taps and
flaps are single, rapid, usually
apical
Apical means "pertaining to an apex". It may refer to:
*Apical ancestor, refers to the last common ancestor of an entire group, such as a species (biology) or a clan (anthropology)
*Apical (anatomy), an anatomical term of location for features loc ...
gestures where the tongue is thrown against the roof of the mouth, comparable to a very rapid stop. These terms are sometimes used interchangeably, but some phoneticians make a distinction. In a tap, the tongue contacts the roof in a single motion whereas in a flap the tongue moves tangentially to the roof of the mouth, striking it in passing.
During a
glottalic airstream mechanism, the glottis is closed, trapping a body of air. This allows for the remaining air in the vocal tract to be moved separately. An upward movement of the closed glottis will move this air out, resulting in it an
ejective consonant. Alternatively, the glottis can lower, sucking more air into the mouth, which results in an
implosive consonant
Implosive consonants are a group of stop consonants (and possibly also some affricates) with a mixed glottalic ingressive and pulmonic egressive airstream mechanism.''Phonetics for communication disorders.'' Martin J. Ball and Nicole Müller. R ...
.
Clicks are stops in which tongue movement causes air to be sucked in the mouth, this is referred to as a
velaric airstream
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for sound pr ...
. During the click, the air becomes
rarefied between two articulatory closures, producing a loud 'click' sound when the anterior closure is released. The release of the anterior closure is referred to as the click influx. The release of the posterior closure, which can be velar or uvular, is the click efflux. Clicks are used in several African language families, such as the
Khoisan and
Bantu languages.
Vowels
Vowels are produced by the passage of air through the
larynx and the
vocal tract. Most vowels are
voiced
Voice or voicing is a term used in phonetics and phonology to characterize speech sounds (usually consonants). Speech sounds can be described as either voiceless (otherwise known as ''unvoiced'') or voiced.
The term, however, is used to refer ...
(i.e. the vocal folds are vibrating). Except in some marginal cases, the vocal tract is open, so that the airstream is able to escape without generating fricative noise.
Variation in vowel quality is produced by means of the following articulatory structures:
Articulators
Glottis
The
glottis is the opening between the vocal folds located in the
larynx. Its position creates different vibration patterns to distinguish voiced and voiceless sounds.
["Laver, John ''Principles of Phonetics'', 1994, Cambridge University Press] In addition, the
pitch of the vowel is changed by altering the frequency of vibration of the
vocal folds
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speec ...
. In some languages there are contrasts among vowels with different
phonation types.
["Peter Ladefoged and Ian Maddieson ''The Sounds of the World's Languages'', 1996, Blackwell; ]
Pharynx
The pharynx is the region of the vocal tract below the velum and above the larynx. Vowels may be made
pharyngealized (also ''epiglottalized'', ''sphincteric'' or ''strident'') by means of a
retraction of the tongue root.
Vowels may also be articulated with
advanced tongue root.
There is discussion of whether this vowel feature (ATR) is different from the Tense/Lax distinction in vowels.
Velum
The velum—or soft palate—controls airflow through the nasal cavity. Nasals and nasalized sounds are produced by lowering the velum and allowing air to escape through the nose. Vowels are normally produced with the
soft palate
The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is the hard palate. ...
raised so that no air escapes through the nose. However, vowels may be
nasalized
In phonetics, nasalization (or nasalisation) is the production of a sound while the velum is lowered, so that some air escapes through the nose during the production of the sound by the mouth. An archetypal nasal sound is .
In the Internationa ...
as a result of lowering the soft palate. Many languages use nasalization contrastively.
Tongue
The tongue is a highly flexible organ that is capable of being moved in many different ways. For vowel articulation the principal variations are
vowel height
A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness and also in quantity (le ...
and the dimension of
backness and
frontness.
A less common variation in vowel quality can be produced by a change in the shape of the front of the tongue, resulting in a
rhotic or rhotacized vowel.
Lips
The lips play a major role in vowel articulation. It is generally believed that two major variables are in effect:
lip-rounding (or labialization) and
lip protrusion.
Airflow
For all practical purposes,
temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer.
Thermometers are calibrated in various Conversion of units of temperature, temp ...
can be treated as
constant in the articulatory system. Thus,
Boyle's Law
Boyle's law, also referred to as the Boyle–Mariotte law, or Mariotte's law (especially in France), is an experimental gas law that describes the relationship between pressure and volume of a confined gas. Boyle's law has been stated as:
The ...
can usefully be written
as the following two equations.
:
:
What the above equations express is that given an initial
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and e ...
''P''
1 and
volume
Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...
''V''
1 at time 1 the
product
Product may refer to:
Business
* Product (business), an item that serves as a solution to a specific consumer problem.
* Product (project management), a deliverable or set of deliverables that contribute to a business solution
Mathematics
* Produ ...
of these two values will be equal to the product of the pressure ''P''
2 and volume ''V''
2 at a later time 2. This means that if there is an increase in the volume of cavity, there will be a corresponding decrease in pressure of that same cavity, and vice versa. In other words, volume and pressure are
inversely proportional
In mathematics, two sequences of numbers, often experimental data, are proportional or directly proportional if their corresponding elements have a constant ratio, which is called the coefficient of proportionality or proportionality constan ...
(or negatively correlated) to each other. As applied to a description of the subglottal cavity, when the lung pistons contract the lungs, the volume of the subglottal cavity decreases while the subglottal air pressure increases. Conversely, if the lungs are expanded, the pressure decreases.
A situation can be considered where (1) the vocal fold valve is closed separating the supraglottal cavity from the subglottal cavity, (2) the mouth is open and, therefore, supraglottal air pressure is equal to atmospheric pressure, and (3) the lungs are
contracted resulting in a subglottal pressure that has increased to a pressure that is greater than atmospheric pressure. If the vocal fold valve is subsequently opened, the previously two separate cavities become one unified cavity although the cavities will still be aerodynamically isolated because the glottic valve between them is relatively small and constrictive.
Pascal's Law
Pascal's law (also Pascal's principle or the principle of transmission of fluid-pressure) is a principle in fluid mechanics given by Blaise Pascal that states that a pressure change at any point in a confined incompressible fluid is transmitted ...
states that the pressure within a system must be equal throughout the system. When the subglottal pressure is greater than supraglottal pressure, there is a pressure inequality in the unified cavity. Since pressure is a
force applied to a
surface area by definition and a force is the product of
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different eleme ...
and
acceleration
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by t ...
according to
Newton's Second Law of Motion, the pressure inequality will be resolved by having part of the mass in air
molecule
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
s found in the subglottal cavity move to the supraglottal cavity. This movement of mass is airflow. The airflow will continue until a pressure equilibrium is reached. Similarly, in an
ejective consonant with a
glottalic airstream mechanism
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for sound pr ...
, the lips or the tongue (i.e., the buccal or lingual valve) are initially closed and the closed glottis (the laryngeal piston) is raised decreasing the oral cavity volume behind the valve closure and increasing the pressure compared to the volume and pressure at a resting state. When the closed valve is opened, airflow will result from the cavity behind the initial closure outward until intraoral pressure is equal to
atmospheric pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...
. That is, air will flow from a cavity of higher pressure to a cavity of lower pressure until the equilibrium point; the pressure as
potential energy is, thus, converted into airflow as
kinetic energy
In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acc ...
.
Sound sources
Sound sources refer to the conversion of aerodynamic energy into acoustic energy. There are two main types of sound sources in the articulatory system: periodic (or more precisely semi-periodic) and aperiodic. A periodic sound source is vocal fold vibration produced at the glottis found in vowels and voiced consonants. A less common periodic sound source is the vibration of an oral articulator like the tongue found in alveolar trills. Aperiodic sound sources are the turbulent noise of fricative consonants and the short-noise burst of plosive releases produced in the oral cavity.
Voicing is a common period sound source in spoken language and is related to how closely the
vocal cord
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speec ...
s are placed together. In English there are only two possibilities, ''voiced'' and ''unvoiced''. Voicing is caused by the vocal cords held close by each other, so that air passing through them makes them vibrate. All normally spoken vowels are voiced, as are all other sonorants except ''h'', as well as some of the remaining sounds (''b'', ''d'', ''g'', ''v'', ''z'', ''zh'', ''j'', and the ''th'' sound in ''this''). All the rest are voiceless sounds, with the vocal cords held far enough apart that there is no vibration; however, there is still a certain amount of audible friction, as in the sound ''h''. Voiceless sounds are not very prominent unless there is some turbulence, as in the stops, fricatives, and affricates; this is why sonorants in general only occur voiced. The exception is during
whispering, when all sounds pronounced are voiceless.
Periodic sources
* Non-vocal fold vibration: 20–40
hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that o ...
(cycles per second)
* Vocal fold vibration
** Lower limit: 70–80 Hz modal (bass), 30–40 Hz creaky
** Upper limit: 1170 Hz (soprano)
Vocal fold vibration
*
larynx:
**
cricoid cartilage
The cricoid cartilage , or simply cricoid (from the Greek ''krikoeides'' meaning "ring-shaped") or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment si ...
**
thyroid cartilage
The thyroid cartilage is the largest of the nine cartilages that make up the ''laryngeal skeleton'', the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilage ...
**
arytenoid cartilage
**
interarytenoid muscles (fold adduction)
**
posterior cricoarytenoid muscle
The posterior cricoarytenoid muscles are small, paired intrinsic muscles of the larynx that extend between cricoid cartilage to the arytenoid cartilages in the larynx.
Structure Origin and insertion
The posterior cricoarytenoid originates f ...
(fold abduction)
**
lateral cricoarytenoid muscle (fold shortening/stiffening)
**
thyroarytenoid muscle
The thyroarytenoid muscle is a broad, thin muscle that forms the body of the vocal fold and that supports the wall of the ventricle and its appendix. It functions to shorten the vocal folds.
Structure
It arises in front from the lower half of the ...
(medial compression/fold stiffening, internal to folds)
**
cricothyroid muscle
The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It is innervated by the superior laryngeal nerve. Its action tilts the thyroid forward to help tense the vocal cords.
Structure
The cricothyroid muscle o ...
(fold lengthening)
**
hyoid bone
**
sternothyroid muscle
The sternothyroid muscle, or sternothyroideus, is an infrahyoid muscle in the neck. It acts to depress the hyoid bone. It is below the sternohyoid muscle. It is shorter and wider than the sternohyoid.
Structure
The sternothyroid arises from the ...
(lowers thyroid)
**
sternohyoid muscle
The sternohyoid muscle is a thin, narrow muscle attaching the hyoid bone to the sternum. It is one of the paired strap muscles of the infrahyoid muscles. It is supplied by the ansa cervicalis. It depresses the hyoid bone.
Structure
The sternohyo ...
(lowers hyoid)
**
stylohyoid muscle
The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the hyoid ...
(raises hyoid)
**
digastric muscle (raises hyoid)
Experimental techniques
*
Plethysmography
A plethysmograph is an instrument for measuring changes in volume within an organ or whole body (usually resulting from fluctuations in the amount of blood or air it contains). The word is derived from the Greek "plethysmos" (increasing, enlar ...
*
Electromyography
*
Photoglottography
*
Electrolaryngography
*
Magnetic resonance imaging (
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
) /
Real-time MRI[.]
*
Radiography
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeu ...
*
Medical ultrasonography
*
Electromagnetic articulography
*
Aerometry
*
Endoscopy
An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inse ...
*
Videokymography
Palatography
In order to understand how sounds are made, experimental procedures are often adopted.
Palatography is one of the oldest instrumental phonetic techniques used to record data regarding articulators. In traditional, static palatography, a speaker's palate is coated with a dark powder. The speaker then produces a word, usually with a single consonant. The tongue wipes away some of the powder at the place of articulation. The experimenter can then use a mirror to photograph the entire upper surface of the speaker's mouth. This photograph, in which the place of articulation can be seen as the area where the powder has been removed, is called a palatogram.
Palatography
/ref>
Technology has since made possible electropalatography (or EPG). In order to collect EPG data, the speaker is fitted with a special prosthetic palate, which contains a number of electrodes. The way in which the electrodes are "contacted" by the tongue during speech provides phoneticians with important information, such as how much of the palate is contacted in different speech sounds, or which regions of the palate are contacted, or what the duration of the contact is.
See also
* Index of phonetics articles
* Manner of articulation
* Place of articulation
In articulatory phonetics, the place of articulation (also point of articulation) of a consonant is a location along the vocal tract where its production occurs. It is a point where a constriction is made between an active and a passive articula ...
* Basis of articulation
In phonetics, the basis of articulation, also known as articulatory setting, is the default position or standard settings of a speaker's organs of articulation when ready to speak. Different languages each have their own basis of articulation, whic ...
* Vowel
A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness and also in quantity (leng ...
* Consonant
In articulatory phonetics, a consonant is a speech sound that is articulated with complete or partial closure of the vocal tract. Examples are and pronounced with the lips; and pronounced with the front of the tongue; and pronounced wi ...
* International Phonetic Alphabet
The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standardized representation ...
* Articulatory phonology
* Airstream mechanism
In phonetics, the airstream mechanism is the method by which airflow is created in the vocal tract. Along with phonation and articulation, it is one of three main components of speech production. The airstream mechanism is mandatory for sound pr ...
* Human voice
* Phonation
* Relative articulation
* Source–filter model
* Vocal tract
Notes
References
Citations
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External links
Interactive place and manner of articulation
QMU's CASL Research Centre site for ultrasound tongue imaging
Seeing Speech – with reference examples of IPA sounds using MRI and ultrasound tongue imaging
Interactive Flash website for American English, Spanish and German sounds
{{IPA navigation
Phonetics
Articles containing video clips