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Place of articulation

In , the place of articulation is the specific point of constriction or closure in the vocal tract where an active approaches or contacts a passive to obstruct and produce a sound. This parameter forms one of three core classificatory features for , alongside (how the obstruction occurs) and voicing (vibration of the vocal folds). Places of articulation vary across languages but are fundamental to distinguishing sounds, such as the bilabial closure for /p/ versus the alveolar contact for /t/ in English. Active articulators, which include the lower lip, tongue tip, tongue blade, tongue body, and root, move toward stationary passive articulators like the upper lip, upper teeth, alveolar ridge, , (velum), , pharyngeal wall, and to create the necessary narrowing. The resulting places are typically described from front to back along the vocal tract, encompassing bilabial (lips together, as in /m/), labiodental (lower lip to upper teeth, as in /f/), dental (tongue to teeth, as in /θ/), alveolar (tongue tip to alveolar ridge, as in /n/), postalveolar (tongue blade behind alveolar ridge, as in /ʃ/), retroflex (tongue tip curled back, as in some /ɹ/ variants), palatal ( body to , as in /j/), velar ( back to , as in /ŋ/), uvular ( back to ), pharyngeal ( root to ), and glottal (constriction at the vocal folds, as in the [ʔ]). While English primarily utilizes about nine of these places, other languages employ additional ones like epiglottal or labiovelar combinations for unique consonants. Understanding place of articulation is crucial in and language teaching, as it underlies sound inventories, phonological rules, and speech disorders involving misarticulation, such as substituting alveolar for dental sounds. Instrumental techniques like electropalatography and ultrasound imaging have advanced the study of these places by visualizing and movements in real time.

Introduction and Fundamentals

Overview

In , the place of articulation refers to the specific location within the vocal tract where the is obstructed or modified to produce a sound, involving the interaction between active articulators (such as the or ) and passive articulators (such as the teeth or ). This parameter is essential for distinguishing , as seen in English where the bilabial stop /p/ is formed by bringing both together to block , while the alveolar stop /t/ involves the tip contacting the behind the upper teeth. The concept emphasizes the anatomical positioning that shapes sound production without delving into the full mechanics of restriction. The classification of places of articulation traces back to ancient Indian grammarians, notably in the 4th century BCE, who systematically described oral places in his , organizing sounds by articulatory sites like the , , and to ensure precise pronunciation in Vedic texts. This early framework influenced later traditions, evolving through medieval Arabic and European scholarship into the modern standards established in the late 19th century by the , which standardized places for cross-linguistic transcription. Place of articulation interacts with (how airflow is obstructed, such as stops or fricatives) and voicing (vibration of the vocal folds) to form the basis of consonant charts in phonetic inventories, allowing systematic categorization of sounds across languages. For instance, in the chart, columns represent places from bilabial to glottal, with rows indicating manners, and voicing distinguishing pairs like voiced /b/ and voiceless /p/ at the bilabial place. Understanding place of articulation is crucial in , where children progressively master consonantal places, often acquiring anterior places like bilabials before posterior ones like velars, influencing developmental milestones. In , it guides interventions for articulation disorders by targeting specific places to correct errors in sound production. Additionally, in , place features enhance automatic systems by modeling articulatory knowledge to improve consonant identification in noisy environments.

Anatomical Foundations

The supralaryngeal vocal tract, extending from the to the , forms the primary and modifier of airflow for above the . This tract includes the oral cavity, , and , where constrictions and resonances shape the acoustic properties of and vowels. Air from the lungs passes through this region, interacting with movable and fixed structures to produce articulatory gestures. Active articulators are the movable components that initiate contact or constriction within the vocal tract to modify . The lower lip can protrude or retract to approximate the upper lip or teeth, facilitating labial sounds. The , the most versatile , is divided into the (apex), blade (front portion), front, back, and ; it raises, lowers, advances, or retracts to contact various passive structures, enabling a wide range of places from alveolar to velar. The lowers or elevates to adjust the overall opening and position, influencing vowel formants and consonant articulation. The velum () raises to close the nasal passage or lowers to allow nasal , directing pathways. Passive articulators are stationary structures against which active articulators move to form constrictions. These include the upper lip for bilabial contact, upper teeth for dental approximations, the alveolar ridge (gum line behind the upper teeth) for alveolar sounds, the for palatal gestures, the and for velar and uvular places, the pharyngeal wall for pharyngeal constrictions, the at the laryngopharynx entrance, and the as the space between the vocal folds. The interaction between active and passive articulators defines the place of articulation, with the degree of constriction determining whether fricatives, stops, or result. The , located below the supralaryngeal tract, primarily controls through the vocal folds but also serves as a site for glottal articulation distinct from supralaryngeal places. The vocal folds vibrate to produce voicing across all supralaryngeal sounds, yet the functions as a passive for glottal fricatives like /h/, where turbulence occurs at the glottal opening without supralaryngeal constriction. This distinction highlights the larynx's dual role in both global voicing and localized glottal gestures. Standard phonetic diagrams, such as mid-sagittal sections of the vocal tract, illustrate these structures in a vertical slice through the head's midline, showing the alignment of articulators from to lips. Modern imaging techniques have enhanced understanding of articulator dynamics beyond static diagrams. Real-time (MRI) captures three-dimensional movements of the , velum, and pharyngeal wall during continuous speech, revealing subtle coarticulation patterns and individual variability. imaging, applied non-invasively to the and jaw, provides high-temporal-resolution data on surface contours and trajectories, offering insights into articulatory timing and adaptation in diverse languages. Recent advances as of 2025 include the of large-scale real-time MRI databases, such as the rtMRIDB for studying vocal tract movements in languages like , and frameworks for automatic phonetic segmentation from images in child speech. These methods confirm the precision of active control and passive surface interactions in real-time .

Primary Places of Articulation

Major Categories and Descriptions

The major places of articulation in phonetics are organized hierarchically along the vocal tract, from the lips to the glottis, reflecting the primary points of constriction or closure during consonant production. These categories group related articulatory positions based on the active articulator (typically the tongue or lips) and the passive articulator (a fixed structure in the vocal tract). The labial places involve the lips, coronal places engage the tongue tip or blade, dorsal places use the tongue body, radical places the tongue root or base, and laryngeal places the glottis. This organization facilitates cross-linguistic comparison and phonetic transcription using the International Phonetic Alphabet (IPA). Labial places include bilabial and labiodental articulations. In bilabial sounds, the two lips approximate to form a , as in the voiceless stop (English "pin") or voiced stop (English "bin"), where is briefly blocked before release. Labiodental articulations involve the lower against the upper teeth, producing fricatives such as the voiceless (English "") and voiced (English ""), with turbulent through the narrow channel. These places are common in but less frequent in others without labiodental fricatives. Coronal places encompass dental, alveolar, postalveolar, and retroflex articulations, all involving the front portion of the tongue () against upper structures. Dental sounds feature the tongue tip or blade contacting the upper teeth, as in the voiceless [θ] (English "thin") and voiced [ð] (English "this"), with friction at the teeth. Alveolar articulations position the tongue tip against the alveolar ridge (the bony ridge behind the upper teeth), yielding stops like (English "tin") and (English "din"), nasals , s [s z], and lateral . Postalveolar (or palato-alveolar) sounds occur slightly behind the alveolar ridge, often with tongue blade raising toward the , as in the s [ʃ] (English "ship") and [ʒ] (English "measure"). Retroflex articulations, less common in languages, involve curling the tongue tip backward to contact the or postalveolar region, producing stops such as [ʈ] and [ɖ], or s [ʂ], as in or . Dorsal places refer to articulations using the body of the tongue against the . Palatal sounds raise the tongue body to the , creating stops [c ɟ], nasal [ɲ], or , as in "caña" for [ɲ]. Velar articulations position the back of the tongue against the (velum), forming stops (English "") and (English "go"), nasal [ŋ] (English "sing"), and fricatives [x ɣ], common across many languages. These places often show coarticulatory effects with adjacent vowels, advancing or retracting based on context. Radical places involve the root or base of the tongue in the lower vocal tract, including uvular, pharyngeal, and epiglottal articulations. Uvular sounds constrict the body against the , producing stops [q ɢ] or fricatives [χ ʁ], as in "qalb" [qalb] or French uvular [ʁ] in "rue". Pharyngeal articulations narrow the using the tongue root against the pharyngeal wall, yielding fricatives [ħ ʕ], prominent in like . Epiglottal sounds, rarer, articulate with the aryepiglottic folds against the , such as the fricative [ʜ] or stop [ʡ], found in languages like Agul (Dagestani). emphatic consonants, such as [sˤ tˤ dˤ], involve secondary at coronal places, enhancing pharyngeal constriction for contrast. Clicks in (e.g., !Xóõ) use lingual ingressive airflow with anterior closures at dental [|], alveolar [!], or palatal [ǂ] places, demonstrating place-specific velaric initiation. Laryngeal place occurs at the , where the vocal folds approximate for the [ʔ] (English "uh-oh") or create friction for (English ""), without involvement of supraglottal structures. This place marks the end of the pulmonic pathway. Traditional classifications sometimes overlook fine distinctions within places, but emerging aerodynamic reveals sub-places through and measurements.

Table of Articulators and Places

The below provides a systematic overview of the primary places of articulation, organized in sagittal progression from the front () to the back () of the vocal tract. This progression reflects the anatomical layout of the oral and pharyngeal cavities, facilitating for production. The active refers to the movable part (e.g., or ) that approaches or contacts the passive , the stationary target (e.g., teeth or ). Columns include representative symbols for consonants at each place and examples of languages where they occur prominently. The covers over 18 places by incorporating standard categories, double articulations, and rare variants documented in linguistic , excluding highly idiosyncratic cases.
Active ArticulatorPassive ArticulatorPlace of ArticulationIPA ExamplesLanguages/Occurrences
Lower lipUpper lipBilabial[p, b, m, ɸ, β]English (e.g., in "pit"), universal
Lower lipUpper teethLabiodental[f, v, ɱ]English (e.g., in "")
Tongue tipUpper lipLinguolabial (rare)[t̼, d̼, n̼]Vao ()
Upper lipLower teethDentilabial (rare)[f͆, v͆]Greenlandic dialects (rare)
Tongue tipUpper teethDental[θ, ð, t̪, d̪, n̪]English (e.g., [θ] in "thin"),
Tongue tip or bladeAlveolar ridgeAlveolar[t, d, n, s, z, l, ɾ, ɹ]English (e.g., in "top")
Tongue bladePost-alveolar regionPostalveolar[ʃ, ʒ, tʃ, dʒ]English (e.g., [ʃ] in "ship")
Tongue tip (curled back)Hard palateRetroflex[ʈ, ɖ, ɳ, ʂ, ɻ] (e.g., [ʈ] in "ṭīk"),
Tongue blade (laminal)Alveolo-palatal (double, rare)Alveolo-palatal[t͡ɕ, d͡ʑ, ɲ̠, ɕ, ʑ],
Tongue bodyHard palatePalatal[c, ɟ, ɲ, ç, j] (e.g., [ɲ] in "nyelv"), English in "yes"
Lips and tongue bodyHard palateLabial-palatal (rare)[c͡β, ɟ͡b]Some West African languages (e.g., )
Tongue bodySoft palateVelar[k, g, ŋ, x, ɣ]English (e.g., in "cat")
Lips and tongue bodySoft palateLabio-velar[k͡p, g͡b, ŋ͡m, w] (e.g., [k͡p] in "kpe"), English in "wet"
Tongue bodyUvulaUvular[q, ɢ, ɴ, χ, ʁ] (e.g., in ""), [ʁ] in "rue"; Archi (endangered Nakh-Daghestanian) features 16 uvular variants including pharyngealised [qˤ, χˤ] from recent fieldwork
Tongue rootPharyngeal wallPharyngeal[ħ, ʕ] (e.g., [ħ] in "ḥarf")
Epiglottis/aryepiglottic foldsPharyngeal wallEpiglottal (rare)[ʡ, ʜ, ʢ, ʡ̞] (, endangered); Agul (Caucasus, endangered) with [ʡ] in stops and fricatives
Vocal foldsGlottisGlottal[ʔ, h, ɦ]English (e.g., [ʔ] in "uh-oh"), universal
This tabular format serves as a quick reference, contrasting with prose descriptions of major categories. For visual representation, refer to sagittal diagrams of articulator positions, such as those illustrating and lip configurations across languages (e.g., updated models incorporating markers for variants like Archi's uvular-pharyngeal interactions).

Variations in Articulation

Homorganic and Coarticulated Consonants

Homorganic consonants are those articulated at the same place of , forming series where multiple manners of articulation share a common location. In English, for instance, the nasal stops /m/, /n/, and /ŋ/ form a homorganic series with the voiceless stops /p/, /t/, and /k/, respectively, all produced at the , alveolar ridge, and velum. This pattern facilitates phonological processes like nasal assimilation, where a adopts the place of a following to create homorganic clusters. Coarticulation involves the overlap of articulatory gestures between adjacent sounds, influencing the realization of place of articulation. Anticipatory coarticulation occurs when a sound is affected by an upcoming segment, such as a velar /k/ shifting toward a palatal place before a high /i/ in languages like English (e.g., "" with advanced position) or Italian (e.g., /ki/ realized as [tɕi]). Perseverative coarticulation, conversely, arises from carry-over effects, as when a preceding velar influences the following vowel's backness in words like "." These coarticulatory effects often lead to phonological , where place features spread between segments. In English, the prefix /ɪn-/ assimilates in place to a following labial, as in "in-possible" becoming "impossible" with sharing the labial place of /p/, a process driven by anticipatory regressive . Similar rules apply cross-linguistically, such as nasal place in , where /n/ becomes homorganic with a following coronal or labial (e.g., /n/ + /t/ → [nt], /n/ + /p/ → [mp]). Diverse languages exhibit coarticulated consonants involving multiple places simultaneously. In Yoruba, labial-velar stops like /kp/ and /gb/ are produced with simultaneous closure at the lips and velum, and preceding nasals assimilate to a homorganic [ŋm] (e.g., in "ọmọ gbọ" 'he hears'). In Somali, coronal consonants coarticulate with pharyngeals, resulting in retracted or pharyngealized realizations that spread pharyngeal constriction forward. Modern research employs acoustic analysis, such as spectrograms, to demonstrate place coarticulation in rapid speech. Locus equations, measuring transitions from consonant release to vowel steady state, reveal anticipatory effects on place cues, with shallower slopes for alveolar versus velar stops indicating less coarticulation for alveolars in English. coefficients in stop bursts further highlight anticipatory place shifts, as seen in VOT and burst spectra varying with following vowels across speakers.

Central, Lateral, and Secondary Articulation

In phonetics, articulation can vary in the direction of airflow through the oral cavity. Central articulation, the default for most consonants, involves airflow primarily through the midline of the mouth, with the tongue or other articulators forming a constriction that directs the airstream centrally. Lateral articulation, by contrast, features a central blockage by the tongue, allowing airflow to escape around one or both sides of the mouth; this produces sounds classified as [+lateral] in feature geometry. Representative examples include the alveolar lateral approximant in English "let," where air flows laterally past the tongue sides, and the voiceless alveolar lateral fricative [ɬ] in Welsh "llaw" (hand), which adds frication to the lateral airflow. Secondary articulation modifies a primary constriction by adding a simultaneous, less prominent gesture elsewhere in the vocal tract, often vowel-like in quality, which alters the sound's timbre without changing the main place of articulation. Common types include labialization, involving lip protrusion and rounding (e.g., the velar stop [kʷ] in Kwakw'ala "kʷesa" meaning 'splashing water,' contrasting with non-labialized in "kasa" 'beat softly'); palatalization, raising the tongue body toward the hard palate (e.g., Russian [tʲ] in "mʲatʲ" 'to rumble,' distinct from velarized [tˠ] in "matʲ" 'mother'); and velarization or pharyngealization, retracting the tongue root (e.g., Arabic emphatic [sˤ] in "sˤaːfɪr" 'whistle,' versus plain in "saːfɪr" 'ambassador'). These secondary gestures are phonemically contrastive in many languages and are transcribed with diacritics in the International Phonetic Alphabet. Double articulation occurs when a secondary gesture achieves equal prominence to the primary one, resulting in two simultaneous strictures of comparable degree, often treated as a single complex segment. Examples include labio-velar stops like [k͡p] in Eggon "àk͡pà" 'kneel,' where lip closure pairs with velar closure, contrasting with sequences like [kp]. Such sounds are rarer than secondary articulations and cluster geographically, appearing mainly in West and Central African languages (e.g., Idoma) and some like Yeletnye [t͡p]. Cross-linguistically, lateral sounds show rich diversity in places of articulation, particularly in Australian languages, where series of dental [ɮ̪], alveolar , retroflex [ɭ], and palatal [ʎ] laterals distinguish meaning; acoustic studies of Arrernte, Pitjantjatjara, and Warlpiri reveal distinct formant patterns, with retroflex laterals showing lower F3 frequencies due to tongue curling. Secondary articulations vary by region: Slavic languages like Russian emphasize palatalization as a tongue body raising feature, creating contrasts via [-back] posture without pharyngeal involvement, while African languages often feature pharyngealization (e.g., Arabic emphatics) or labial-velar doubles in Bantu and Niger-Congo families. Recent articulatory modeling studies address secondary places in click languages like !Xóõ, a of , using biomechanical simulations to show how biases click production; these models demonstrate reduced effort for certain secondary velar or uvular accompaniments to the primary anterior click influx, influencing acoustic output and cross-linguist .