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Manner of articulation

Manner of articulation is a fundamental concept in that describes how the airstream from the lungs is obstructed, constricted, or otherwise modified by the in the vocal tract to produce sounds. It focuses on the degree of closure or narrowing between the active (such as the or ) and the passive (such as the teeth, alveolar ridge, or velum), which determines the acoustic and auditory qualities of the sound. Consonants are classified into several main manners based on this airflow modification, including stops (also called plosives), where the airstream is completely blocked in the oral cavity before being released, as in , , and ; fricatives, where the articulators are close enough to cause turbulent friction, as in , , and [ʃ]; and affricates, which combine a stop closure followed by fricative release, as in [tʃ] and [dʒ]. Other key manners encompass nasals, in which the velum is lowered to allow airflow through the while the mouth is closed, such as , , and [ŋ]; approximants (including glides and liquids), featuring minimal obstruction without significant friction, as in , , , and [ɹ]; and flaps or trills, involving brief or vibrating interruptions of airflow, like the alveolar flap [ɾ] in . This classification, often combined with (the location of ) and voicing (vibration of the vocal folds), provides a systematic framework for describing and comparing inventories across languages. For instance, English has a relatively limited set of manners compared to languages like !Xóõ, which includes clicks as an additional manner involving ingressive oral . Understanding manner of articulation is essential for , language teaching, and phonological analysis.

Core Concepts

Definition and Scope

Manner of articulation refers to the specific way in which the from the lungs—or, in some cases, other mechanisms—is obstructed or modified by the articulators in the vocal tract to produce , particularly . This focuses on the degree and type of or formed by the active and passive articulators, such as the , , and , which shapes the acoustic properties of without regard to the precise location of the constriction. For instance, complete of the vocal tract temporarily blocks to create a stop, while a narrow allows turbulent to produce a . The concept of manner of articulation emerged in phonetic theory during the , building on the pioneering work of linguists such as Henry Sweet, who advanced systematic classifications of in works like his Handbook of Phonetics (1877). Sweet's contributions laid foundational principles for describing how articulatory configurations affect sound production, influencing subsequent scholars including , who further refined phonetic notation in the early . Modern standardization of manner descriptions occurred through the , established by the in 1886, with Sweet as an early member; the IPA provides a universal framework for transcribing manners consistently across languages. Manner of articulation plays a crucial role in phonological contrasts, enabling languages to distinguish meaning through variations in modification, which directly impacts speech intelligibility and the composition of sound inventories. For example, in English, the voiceless bilabial stop /p/ (with full closure) contrasts with the /f/ (with narrowing), as in "" versus "," where differences in manner create minimal pairs that alter word meaning. This feature allows languages to build diverse systems, with some prioritizing certain manners to encode phonological oppositions essential for communication clarity.

Relation to Place of Articulation and Airstream

Manner of articulation specifies the configuration of the vocal tract articulators that modifies the to produce a , while identifies the precise location of that modification along the vocal tract. Together, these parameters define the essential characteristics of consonants, with manner addressing the "how" of obstruction and place the "where." For example, in the /p/, the manner is , involving complete closure and sudden release of , combined with a bilabial place where the meet to form the obstruction. Airstream mechanisms provide the foundational that manner and place act upon, determining the direction and source of air movement through the vocal tract. The predominant mechanism in most languages is pulmonic egressive, in which air is expelled outward from the lungs via contraction of the respiratory muscles, serving as the basis for standard manners like stops and fricatives. Non-pulmonic mechanisms, such as those used in ejectives or clicks, alter the direction and intensity, thereby influencing compatible manners. Conceptual models of distinguish pulmonic flow as steady and outward, contrasting with the localized pressure bursts in other types, which require coordinated movements to avoid disrupting the primary manner. The coordination of manner, place, and is central to phonetic classification systems, such as the International Phonetic Alphabet () consonant chart, where places of are arrayed horizontally (from bilabial to glottal) and manners vertically (from plosives to ), with pulmonic egressive as the default modified by symbols for non-pulmonic variants. This integration allows for systematic representation; the alveolar /s/, for example, results from a narrow groove formed by the tongue tip against the alveolar ridge (place: alveolar), creating frictional turbulence in the pulmonic egressive (manner: ). Such combinations highlight how provides the dynamic energy, place sets the anatomical site of interaction, and manner dictates the degree and type of stricture, enabling diverse sound inventories across languages. Understanding these relations presupposes knowledge of vocal tract , where articulators like the (for coronal and places), (for labial places), and velum (for routing to the in nasal manners) enable the modifications. The 's flexibility, for instance, allows precise adjustments at multiple places to achieve varying manners, while the velum's elevation or lowering directs pulmonic airflow orally or nasally, foundational to manner distinctions without altering the primary . This anatomical interplay ensures that manner and place operate in concert with to produce perceptually distinct sounds, forming the prerequisites for analyzing systems in .

Classification Frameworks

Obstruents and Sonorants

Obstruents are characterized by significant obstruction of the in the vocal tract, resulting in or complete blockage that produces noisy or silent acoustic effects. This class includes sounds subdivided by the degree of stricture, such as stops (with full closure) and fricatives (with partial narrowing causing friction). Articulatorily, obstruents involve a sufficiently narrow vocal tract configuration that generates even with voiced , classifying them as [-sonorant] in feature systems. In contrast, sonorants are produced with minimal obstruction of the , permitting free in the oral or nasal cavities and yielding periodic, vowel-like acoustic qualities. Examples encompass nasals, , liquids, glides, and vowels, all marked as [+sonorant] due to their open vocal tract allowing unimpeded without . Acoustically and articulatorily, obstruents exhibit low sonority from pressure buildup and aperiodic noise, whereas sonorants display high sonority through sustained periodic voicing and resonant formants. The basic ranks obstruents as the least sonorous, ascending through nasals and liquids to glides and vowels at the peak. Phonologically, obstruents typically occupy syllable margins, such as onsets, where they create perceptual contrast through their abrupt, non-resonant profiles; for instance, the English voiceless stop /t/ in "top" functions as an onset. Sonorants, by virtue of their higher sonority, often form syllable nuclei or act as glides, supporting the core resonance of syllables; the English nasal /m/ in "man" exemplifies a in a marginal position but with resonant properties akin to a nucleus. This binary distinction underlies cross-linguistic patterns in syllable structure and , with obstruents favoring positions for demarcation and sonorants enabling sustained sonority peaks.

Degrees of Stricture

The degree of stricture refers to the extent to which the airflow through the vocal tract is obstructed by the articulators during the production of , forming a gradient scale that serves as the foundational framework for classifying manners of from maximal obstruction to minimal interference. This scale ranges from complete , where airflow is fully blocked, to open , where the tract remains relatively unobstructed, allowing smooth passage of air. The stricture organizes manners accordingly: complete characterizes plosives, involving total that builds up intraoral until release; near- with defines fricatives, where a narrow channel generates frictional noise; momentary followed by fricative release distinguishes affricates; nasal diversion occurs with complete oral but lowered velum, as in nasals; and open passage typifies , with sufficient space to avoid . This underpins the obstruent-sonorant binary, where obstruents exhibit greater stricture (complete or near-complete) than sonorants (nasal or open). Articulatorily, stricture arises from the proximity of active and passive articulators, creating differentials that determine acoustic outcomes: full produces due to blocked and buildup behind the , while partial strictures accelerate air velocity through constrictions, leading to in fricatives. In frication, the narrowing invokes conceptually, where increased speed reduces , destabilizing the jet and promoting turbulent eddies that generate noise without requiring equations for description. For nasals and , the mechanics involve either a secondary nasal pathway or wider oral spacing, maintaining resonant without significant imbalance. Phonetic measurement of stricture relies on qualitative scales, such as those in the , which categorize manners based on articulatory constriction degrees without numerical precision, emphasizing perceptual and production distinctions. Acoustically, correlates distinguish stricture levels: fricatives exhibit broadband noise spectra from turbulent energy, often in high-frequency ranges, whereas show clear structures resembling vowels due to periodic voicing and minimal obstruction. Plosives, meanwhile, feature silence during closure followed by burst transients, and nasals display lowered intensities with nasal murmurs. Variations in stricture include central versus lateral configurations: central stricture obstructs the vocal tract midline, forcing air through peripheral channels, while lateral stricture permits along the sides despite central approximation, as seen in certain or fricatives. In modern articulatory , stricture is further nuanced by gestural overlap, where overlapping articulatory gestures for adjacent sounds can modulate effective constriction degrees, influencing manner transitions through spatiotemporal coordination rather than isolated closures.

Primary Manners of Articulation

Plosives

Plosives, also known as stops, are consonants characterized by a complete of the vocal tract that blocks oral , followed by the buildup and sudden release of intraoral . This manner of articulation involves three primary stages: the , in which the articulators form a tight seal at the to prevent air escape; the hold , during which subglottal air increases behind the , creating a pressure differential; and the release , marked by an abrupt opening that results in a brief burst of sound as the is expelled. Plosives represent the stricture degree of complete , distinguishing them from manners with partial obstruction. Common types of plosives include voiceless variants such as /p/, /t/, and /k/, produced without vocal fold during the hold and release, and voiced counterparts like /b/, /d/, and /g/, where the vocal folds vibrate throughout or primarily during the hold phase. Additional variants occur cross-linguistically, including aspirated plosives (e.g., /pʰ/, /tʰ/, /kʰ/), in which a puff of glottal airflow follows the release, as in English word-initial positions or languages like ; and pre-nasalized forms (e.g., /ᵐb/, ⁿd/, ᵑɡ/), featuring a preceding homorganic nasal element with lowered velum during the initial closure, common in such as . These variants often function phonologically as unitary segments despite their complex articulation. Acoustically, plosives exhibit a period of silence or low-amplitude during the closure phase due to the absence of , followed by a transient burst—a short, noise-like release spectrum that varies by —and subsequent transitions into adjacent vowels that provide cues for identification. For instance, bilabial bursts are diffuse with low-frequency energy, while alveolar bursts show mid-frequency concentration. Plosives are universally present in the world's languages, with voiceless /p/, /t/, and /k/ appearing in nearly all, and labial plosives like /p/ occurring in approximately 93% of sampled languages, underscoring their fundamental role in human speech inventories. In , plosives frequently participate in processes like , where they are lengthened or doubled to signal morphological or lexical contrasts, as in (e.g., /p/ in appa vs. apa) or , enhancing duration in the hold phase for perceptual distinction. Prenasalized plosives similarly serve contrastive functions, behaving as single phonemes that trigger nasal or tone depression in languages like , while also stabilizing voicing in systems. These roles highlight plosives' versatility in structuring syllables and words across diverse linguistic families.

Fricatives

Fricatives are sounds produced by directing through a narrow in the vocal tract, generating turbulent and characteristic frication . This partial stricture divides the vocal tract into anterior and posterior cavities, with the of the anterior cavity influencing the resonant frequencies of the spectrum. Unlike complete closures, this sustained turbulence allows continuous sound production without interruption. Fricatives are classified as sibilant or non-sibilant based on the and of their . , such as /s/ and /ʃ/, exhibit high-amplitude, high-frequency hissing due to articulatory features like a grooved directing against the alveolar or , enhancing in the 4-8 kHz range. Non-sibilant fricatives, like /f/ and /θ/, produce lower- with broader spectral energy, often lacking the sharp sibilance because of less focused , as in labiodental or dental articulations. Voicing in fricatives introduces periodic vocal fold superimposed on the aperiodic frication . Voiceless fricatives, exemplified by /s/, feature aspiration-like turbulent without vocal cord involvement, resulting in higher amplitude and longer duration compared to their voiced counterparts. Voiced fricatives, such as /z/, combine the frication with low-frequency energy from voicing, but aerodynamic constraints often lead to partial devoicing or shorter durations to maintain subglottal pressure for . Acoustically, fricatives are analyzed through spectral properties, including peaks and moments like center of gravity (spectral mean), which decrease posteriorly (e.g., /s/ at 5-6 kHz versus /ʃ/ at 4-4.5 kHz). Sibilants show concentrated high-frequency energy, while non-sibilants have more diffuse spectra; formant transitions from adjacent vowels further aid place distinctions, such as between /f/ and /θ/. Articulatory adjustments, like tongue grooving for sibilance, sharpen these spectral peaks, as confirmed by methods like multitaper spectral estimation for robust measurement. Cross-linguistically, fricatives occur in about 91% of the world's languages, but they are rarer in some isolates, where they often appear primarily in loanwords rather than core vocabulary. In languages like , the broadband noise of fricatives can interact with lexical , influencing manner identification through masking of cues or altered spectral contrasts.

Affricates

Affricates are characterized by a manner of articulation that involves a complete oral , akin to a , followed by a slow release producing fricative-like turbulence at the same articulatory location. This sequential process creates a complex sound unit where the is first obstructed entirely before transitioning to partial obstruction, generating through . For instance, the English /tʃ/, as in "," begins with an alveolar ridge released into post-alveolar frication. Affricates occur in approximately 60% of the world's languages, less universally than plosives or fricatives. A key distinction exists between true affricates and pseudo-affricates. True affricates function as single phonemes with a monophthongal, unitary transition from closure to frication, maintaining consistent voicing throughout—such as the voiced /dʒ/ in English "," where the stop and phases share voicing. In contrast, pseudo-affricates are sequences of distinct segments (a stop followed by a ), often allowing independent voicing or prosodic behavior, as seen in minimal pairs like "czy" (true affricate /tɕ/) versus "trzy" (pseudo-affricate /tʂ/). This differentiation can be phonemically contrastive in languages like . Phonetically, affricates exhibit variable duration ratios between the stop closure and fricative release phases, influenced by , position, and speaking rate. The fricative phase often dominates the overall duration, contributing to the perceptual unity of the segment and aiding distinction from fricative-only sounds. Affricates combine and strictures but are treated as a hybrid manner. Historically, affricates frequently evolve from palatalized stops through sound changes that introduce frication during release, as documented in languages like Laomian where bilabial or velar develop affrication post-palatalization. In African languages, affricate clusters are notable, such as lateral affricates in varieties, where they form part of expanded inventories including series of and affricates.

Sonorant Manners

Nasals

Nasal consonants are produced by creating a complete in the oral cavity at some point of while simultaneously lowering the velum to allow airflow through the . This results in the sound being channeled exclusively through the , with the oral tract serving as a side branch that contributes to the acoustic properties. Common places of articulation for nasals include bilabial (/m/), alveolar (/n/), and velar (/ŋ/), aligning with typical oral stop positions in many languages. Nasals are typically voiced due to the steady airflow required for their production, which sustains vocal fold vibration, although voiceless nasals occur in some languages (e.g., Burmese, certain Tibeto-Burman languages). Their resonance is characterized by low-frequency formants arising primarily from the pharyngeal-nasal airway, creating a distinct nasal timbre. Additionally, the closed oral cavity introduces anti-resonances, or zeros in the spectrum, that further shape the sound by attenuating certain frequencies. Phonologically, nasals participate in processes such as prenasalization, where a nasal precedes a stop in clusters like /ᵐb/ or /ⁿd/, often treated as single units in languages with such sequences. Post-nasal contexts frequently trigger voicing , where following obstruents become voiced, as seen in patterns across many languages. While nasal consonants are nearly universal, their inventories vary, typically limited to places matching oral stops, with bilabial, alveolar, and velar nasals being the most common and labiodental nasals rare. Acoustically, nasals feature a low-amplitude nasal murmur during the , distinguished by broad peaks and transitions that reflect the . These transitions provide cues for perception, with coarticulatory effects extending to adjacent vowels. Recent research highlights how children acquire nasal coarticulation gradually, achieving adult-like coordination of velum lowering and oral gestures by around age five, aiding .

Approximants

Approximants are consonants characterized by a degree of stricture in which the articulators approach each other but remain sufficiently distant to allow smooth, laminar through the vocal tract without generating turbulent . This open stricture, narrower than that of vowels yet wider than fricatives, results in central approximation where passes primarily through the midline of the . Representative examples include the labiovelar approximant /w/, formed by the lips and raising the back of the toward the velum, and the palatal approximant /j/, produced by raising the front of the toward the . A key subtype of approximants consists of glides, also termed semivowels, which are vowel-like in articulation but function as due to their non-syllabic role and shorter duration. For instance, /j/ in English "" acts as a glide preceding a , exhibiting a rapid articulatory transition from a high position, while in diphthongs like that of "," it serves as a offglide following the nucleus. Their realization is highly context-dependent, with duration typically brief (often under 100 ms) and influenced by surrounding vowels, leading to allophonic variation where they may approach fricative-like quality in rapid speech. Acoustically, display patterns closely resembling those of adjacent , characterized by steady-state and gradual transitions rather than abrupt changes or noise. The palatal /j/ features a high second ( around 1,850–2,100 Hz), mirroring the high /i/, while the labiovelar /w/ shows a lowered (600–850 Hz) due to back constriction and , which also reduces overall intensity. These properties enable to contribute to formation, providing smooth offglide transitions that enhance quality contrasts without introducing spectral turbulence. Cross-linguistically, approximants frequently occur as offglides in diphthongs, with glides like /j/ and /w/ present in the inventories of over 90% of sampled languages according to phonological database analyses. Their distribution shows variation, as they often hold marginal phonological status in languages emphasizing obstruent contrasts, and in click languages of southern Africa, approximants typically manifest as secondary articulations accompanying ingressive clicks rather than as standalone primary manners.

Laterals and Rhotics

Lateral are consonantal sounds produced with a partial central blockage in the vocal tract, where the is directed around the sides of the . This manner involves the making contact at a central , such as the alveolar ridge, while the sides of the are lowered to allow unobstructed lateral without . The alveolar lateral approximant /l/, found in languages like English and , exemplifies this, with the tip raised to the alveolar ridge and air escaping bilaterally or unilaterally. Retroflex lateral approximants like /ɭ/, occurring in such as , feature the tip curled backward toward the , maintaining the lateral pathway. A key variation in alveolar laterals is the distinction between clear and dark realizations, determined by . Clear /l/ maintains a neutral body position, promoting a fronted vowel-like quality, as in syllable-initial positions in English (e.g., ""). In contrast, dark /l/ involves , where the body raises toward the velum, creating a back, rounded co-articulation similar to a velar , typically in syllable-coda positions (e.g., "full"). Rhotics constitute a diverse class of sonorants characterized by vibratory or bunched configurations that produce a distinctive "r"-like quality, often involving , flap, or manners. Common types include the alveolar /r/, produced by rapid vibration of the tip against the alveolar ridge as in or ; the alveolar flap /ɾ/, a brief single-contact as in intervocalic "butter"; and the postalveolar /ɹ/, a smooth non-vibratory approximation in English. These realizations vary widely across languages, with over 75% of the world's languages featuring at least one rhotic, often contrasting multiple types (e.g., flap vs. in ). As sonorants, rhotics exhibit minimal stricture, allowing periodic voicing with low airflow obstruction. Articulatory diversity extends to obstruent variants of laterals and specific rhotic configurations. Lateral fricatives, such as the voiceless alveolar /ɬ/ in Welsh or , function as s by narrowing the lateral channels to generate turbulent airflow and frication, contrasting with approximant laterals in manner while sharing lateral directionality. In American English, rhotics frequently employ a bunched , where the body and sides elevate centrally without retroflexion, creating a medial near the . Rhotics present notable phonetic challenges, particularly their instability during acquisition, often resulting in late mastery and frequent misarticulations across languages due to the need for coordinated dual gestures (e.g., front raising and root retraction). studies post-2020 have illuminated these complexities, revealing consistent pharyngeal involvement in rhotic production; for instance, rhotics show variable bunching and retroflexion patterns influenced by vowel context, with tongue root advancement contributing to articulatory stability. Similarly, investigations of uvular rhotics in languages like Upper Sorbian confirm tongue root gestures lowering the second , underscoring the multi-gestural nature of rhotics.

Non-Pulmonic and Secondary Manners

Implosives and Ejectives

Implosives and ejectives are non-pulmonic consonants produced using a glottalic airstream mechanism, where airflow is initiated by movements of the larynx rather than the lungs. These sounds modify the basic plosive manner of articulation by incorporating glottal closure alongside oral closure, but with distinct directional airflow patterns. Implosives are produced with an ingressive glottalic airstream, involving a closed glottis and a downward movement of the larynx that creates rarefaction, or negative pressure, in the supraglottal cavity, drawing air inward upon release of the oral closure. The velum is raised to seal the nasal cavity, preventing air escape, and the vocal folds typically vibrate during this process, resulting in voiced implosives such as the bilabial /ɓ/ or alveolar /ɗ/. This inward pull contrasts with pulmonic plosives by generating a sucking effect rather than explosive outflow. In languages like Sindhi, implosives form a phonemic contrast with voiced plosives, appearing in words like /ɓəɾi/ ('child') and contributing to the language's four implosive series at bilabial, dental, palatal, and velar places of articulation. Ejectives, in contrast, employ an egressive glottalic , where the closed is raised upward, compressing air in the sealed supraglottal to build positive for an outward burst upon oral release. This mechanism ensures , as the vocal folds remain approximated without , producing sounds like the bilabial /pʔ/ or alveolar /tʔ/ (often transcribed as /p'/, /t'/). The supraglottal buildup creates a sharper, more abrupt release than in pulmonic voiceless plosives. Ejectives are prevalent in Caucasian languages such as , where they contrast with plain stops in series like /p, p', pʰ/, and in Native American languages like , featuring ejective stops and affricates across multiple places of articulation. The core production difference lies in larynx displacement: lowering for implosives to induce rarefaction and inward , versus raising for ejectives to generate supraglottal and outward ejection, with implosives typically voiced and ejectives voiceless due to phonatory constraints. Both lack the pulmonic that enables voicing in standard stops, often integrating phonologically as obstruents despite variable behavior in processes like or coda positioning. In typological surveys, glottalized consonants like these occur in about 27% of sampled languages, with ejectives in 16% (primarily in the and ) and implosives in 13% (concentrated in and ), though recent documentation reveals their presence in select of .

Clicks and Other Lingual Egressive Sounds

Clicks are produced using a lingual ingressive , in which air is drawn into the mouth by lowering the body after creating a sealed pocket of air between two oral . The posterior is formed by raising the back of the against the velum, while the anterior occurs at a forward point such as the teeth, alveolar ridge, or lips; upon release of the anterior , the rarefied air produces a characteristic suction pop. This velaric mechanism contrasts with pulmonic airstreams by relying solely on for initiation, without involvement of the lungs. The primary types of clicks are distinguished by the location of the anterior closure and are represented in the International Phonetic Alphabet (IPA) with symbols such as dental /ǀ/ (as in the "tsk" sound), alveolar /ǃ/, palatal or palato-alveolar /ǂ/, lateral /ǁ/ (side-released from the alveolar region), and bilabial /ʘ/ (using lip closure). These occur prominently in Khoisan languages of southern Africa, such as Nama (with dental, alveolar, palatal, and lateral clicks) and !Xóõ (with up to 20 click distinctions), where they function as phonemic consonants in word-initial positions. Clicks are typically accompanied by a secondary pulmonic egressive at the posterior closure, which determines their manner: tenuis clicks are voiceless and unaspirated (e.g., /kǀ/ in Nama, with velar release); aspirated clicks involve breathy release (/kǀʰ/); nasal clicks feature velum lowering for nasal airflow (/ŋǀ/ voiced or /ŋ̊ǀ/ voiceless); and glottalized clicks include a (/ʔǀ/). Voiced nasal accompaniments, common in , combine the ingressive click influx with simultaneous voicing and nasal resonance from the lungs. Phonologically, clicks are not standalone but ingressive influxes modified by these accompaniments, functioning as complex segments in the onset. Other lingual sounds include rare egressive variants, where the velaric mechanism expels air outward through reversed tongue movement, though such sounds are unattested in natural languages and limited to theoretical or imitative contexts; suction-based ingressives dominate, as in percussive or interactive clicks. Clicks have spread historically from substrates into through contact, with borrowing evident in like and , where dental, alveolar, and lateral clicks were incorporated as early as Proto-Nguni around the 15th century. Phonetically, the velum's role in sealing the oral cavity is crucial for maintaining the pressure differential during click formation, preventing air escape until release. Acoustically, clicks exhibit a sharp transient pop at release (with higher intensity in percussive types, around 60-80 dB), followed by low-frequency noise and formant structure influenced by cavity size; for instance, dental clicks show a lower center of gravity (spectral centroid) than lateral ones due to front cavity resonance. Documentation has also included Australian languages, notably the Damin ritual register of the Lardil language (now extinct), which features five click types (dental, lateral, etc.) outside Africa, highlighting convergent evolution in isolated linguistic traditions.