Articulatory phonetics

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. See Wikipedia's guide to writing better articles for suggestions. (April 2020) (Learn how and when to remove this template message) This article may lack focus or may be about more than one topic. Please help improve this article, possibly by splitting the article and/or by introducing a disambiguation page, or discuss this issue on the talk page. (April 2020) (Learn how and when to remove this template message)

The field of articulatory phonetics is a subfield of

Valves 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 folds, 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 (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

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).[3] 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.^[4] 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,^[5] 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.^[6] 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.^[7]

Labiodental consonants are made by the lower lip rising to the upper teeth. Labiodental consonants are most often fricatives while labiodental nasals are also typologically common.^[8] There is debate as to whether true labiodental plosives occur in any natural language,^[9] though a number of languages are reported to have labiodental plosives including Zulu,^[10] Tonga,^[11] and Shubi.^[9] Labiodental affricates are reported in Tsonga^[12] 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.^[8]

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.^[13][14] They exist in a number of languages indigenous to Vanuatu 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.^[14]

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

Dental consonants 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 consonants 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.^[17]

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

Retroflex consonants 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.^[22] Typical examples of sub-apical retroflex stops are commonly found in Dravidian languages, 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.^[23] Acoustically, retroflexion tends to affect the higher formants.^[23]

Articulations taking place just behind the alveolar ridge, known as

Radical consonants either use the root of the tongue or the epiglottis during production.^[30]

Pharyngeal consonants are made by retracting the root of the tongue far enough to touch the wall of the pharynx. Due to production difficulties, only fricatives and approximants can be produced this way.^[31][32]

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.^[13]

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.^[36]

Nasals (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.^[40]

In an

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.^[39] 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.^[41] 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.^[42] The stricture is formed in such a way that the airstream causes a repeating pattern of opening and closing of the soft articulator(s).^[43] Apical trills typically consist of two or three periods of vibration.^[44]

Vowels are produced by the passage of air through the larynx and the vocal tract. Most vowels are voiced (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

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.^{[50]: 306–310} Vowels may also be articulated with advanced tongue root.^[49]: 298 There is discussion of whether this vowel feature (ATR) is different from the Tense/Lax distinction in vowels.^{[50]: 302–6}

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 raised so that no air escapes through the nose. However, vowels may be nasalized as a result of lowering the soft palate. Many languages use nasalization contrastively.^{[50]: 298–300}

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

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,

${\displaystyle P_{1}V_{1}=P_{2}V_{2}\,}$^[51]

${\displaystyle {\frac {V_{1}}{(V_{1}+\Delta V)}}={\frac {(P_{1}+\Delta P)}{P_{1}}}}$^[52]

What the above equations express is that given an initial

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

• Non-vocal fold vibration: 20–40 hertz (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
  • thyroid cartilage
  • arytenoid cartilage
  • interarytenoid muscles (fold adduction)
  • posterior cricoarytenoid muscle (fold abduction)
  • lateral cricoarytenoid muscle (fold shortening/stiffening)
  • thyroarytenoid muscle (medial compression/fold stiffening, internal to folds)
  • cricothyroid muscle (fold lengthening)
  • hyoid bone
  • sternothyroid muscle (lowers thyroid)
  • sternohyoid muscle (lowers hyoid)
  • stylohyoid muscle (raises hyoid)
  • digastric muscle (raises hyoid)

Experimental techniques

• Plethysmography
• Electromyography
• Photoglottography
• Electrolaryngography
• MRI) / Real-time MRI^[53]
• Radiography
• Ultrasound tongue imaging
• Electromagnetic articulography
• Aerometry
• Endoscopy
• 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.^[54] 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.^[55]

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

Notes

References