Faucial Pillars – Voice Science

Definition

The faucial pillars are the visible muscular ridges at the back of your mouth that frame the entrance to the throat—the structures voice teachers refer to when discussing “open throat” technique. Anatomically, they are paired arches forming the lateral boundaries of the isthmus of fauces, the narrow gateway connecting the oral cavity to the  Oropharynx. The anterior faucial pillar (palatoglossal arch) is formed by the Palatoglossus muscle, while the posterior faucial pillar (palatopharyngeal arch) is formed by the Palatopharyngeus muscle. Between these pillars lies the tonsillar fossa containing the palatine tonsil.

Context

Relevance to Singing

The faucial pillars have been central to voice pedagogy for over two centuries under the concept of “la gola aperta” (the open throat), yet rigorous scientific documentation of their specific role in phonation has emerged only within the last 40 years through MRI imaging and acoustic analysis. Current evidence suggests that pharyngeal widening associated with faucial pillar positioning contributes significantly to the Singer’s Formant cluster around 2.4-3.0 kHz in classical singing.

For singers, understanding these structures explains the physiological basis for traditional “open throat” instructions. Research by Johan Sundberg established that a pharynx-to-larynx tube area ratio of at least 1:6 is required for singer’s formant production. Recent MRI studies demonstrate that professional singers show pharyngeal width increases of 21.9% and hypopharyngeal volume expansion of 16.8% during classical singing compared to speech (Mainka et al., 2015).

The contrast between classical and Contemporary Commercial Music (CCM) techniques highlights how differently these structures can be employed. Classical singing emphasizes pharyngeal expansion through Larynx lowering and Soft Palate elevation, while Belting involves a less elevated soft palate position, pharyngeal wall narrowing, and laryngeal raising—contrasting configurations for different acoustic goals.

Historical Context and Terminology

The term “fauces” (Latin for “throat” or “gullet,” first attested in English around 1540) refers to the throat opening itself, while “pillars of fauces” or “faucial pillars” describe the muscular arches bounding this space. Otolaryngologists and speech pathologists frequently use “tonsillar pillars” or “palatine arches” interchangeably. The term “oropharyngeal isthmus” was introduced to replace the older “isthmus faucium,” though both remain in use.

Voice pedagogues often reference these structures metaphorically through phrases like “dome of the pharynx” or describe the sensation of “visible pillars” in the oral cavity. The “beginning of a yawn space” gives singers a natural reference point for the raised velum, open pharynx, relaxed tongue, neck and jaw, and raised zygomatic arch characteristic of classical singing.

Scientific Basis

Anatomical Structure

The foundational anatomical study by Kuehn and Azzam (1978) established that the palatoglossus has a flattened belly within the faucial pillar with fan-shaped termination in the palate and vertical tapering termination in the tongue. The anterior pillar contains an elastic fiber sheath with a density gradient increasing from tongue to soft palate, while the collagenous framework allows expansion of pillars but prevents rupture at extreme extension.

The palatopharyngeus muscle arises from the hard palate and palatine aponeurosis and inserts into the posterior border of the Thyroid Cartilage and lateral pharyngeal wall. Its fiber composition—predominantly fast-twitch Type II fibers—allows quick contraction but makes it susceptible to fatigue, potentially explaining why sustained pharyngeal positioning in singing requires significant training.

A critical anatomical distinction: the palatoglossus is uniquely the only tongue muscle not innervated by the Hypoglossal Nerve (CN XII); instead, it receives motor innervation from the pharyngeal plexus via the Vagus Nerve (CN X), reflecting its origin from the fourth branchial arch rather than the occipital myotomes. Research by Mu and colleagues using Sihler’s staining has demonstrated that both muscles contain at least two distinct neuromuscular compartments, suggesting sophisticated independent control of different muscle portions.

Biomechanical Function

The biomechanical modeling study by Gick and colleagues (2014) revealed that the palatoglossus muscle forms an almost complete ring running through the whole oropharyngeal isthmus, functioning as the “primary single muscle of the OPI” with sphincter-like operation similar to the lips. Activation produces narrowing of the isthmus through medial compression of anterior faucial pillars, increased contact between anterior pillars and tongue, and a characteristic “hugging” of the pillars around the tongue with concomitant small tongue raising and velum lowering.

The palatopharyngeus assists swallowing and elevates the larynx, which assists in the phonation of high-pitched sounds. The combined activation of both muscles produces what voice researchers describe as a “sling effect” essential for certain consonant articulations and potentially for vocal tract shaping in singing.

Imaging Research Findings

MRI studies by Echternach and colleagues (2016) examined professional operatic singers, finding that pharynx width increased significantly with both rising pitch and greater loudness (p<0.01). Professional opera tenors maintaining “voix mixte” (Mixed Voice) above the Passaggio showed widened pharynx, increased lip and jaw openings, and increased jaw protrusion, with effects stronger in dramatic tenors than lyric tenors.

A 2025 study using Cone-Beam CT examined the oropharyngeal isthmus in 14 soprano and 12 tenor professional singers, specifically assessing lateral wall dynamics of the isthmic space and motor patterns of palatine veil pillars—one of the few studies directly targeting faucial pillar behavior during singing.

Pedagogical Considerations

The “Open Throat” Concept

Voice pedagogy sources define opening the throat as “a technique whereby pharyngeal space is increased and/or the ventricular (False Vocal Folds) are retracted in order to maximize the resonating space in the vocal tract.” This involves raising the soft palate, lowering the larynx, and assuming ideal positions of articulators including the jaw, lips, and tongue.

The Mitchell and Kenny studies (2003-2004) provided empirical validation: when 15 expert judges evaluated recordings from 6 advanced singing students under optimal (maximal open throat) and sub-optimal conditions, they correctly identified the open throat sound with 85% accuracy. Vibrato extent and onset varied significantly with open throat technique, indicating that “open throat is important to the production of a good sound in classical singing.”

Training Effects

Research consistently demonstrates differences between trained and untrained singers’ pharyngeal behavior. Untrained subjects show elongated uvula, more tilted larynx, highest tongue point positioned more anteriorly, and narrower pharynx compared to professional singers. Larynx height variation is characteristic of untrained singing (Howard, 2009).

Singer’s formant development appears directly linked to pharyngeal configuration changes. Trained singers show more energy concentration in the singer’s formant region (2.4-3.6 kHz) in both sung and spoken vowels compared to untrained speakers, suggesting training effects carry over from singing to speech (Lee et al., 2008).

Style-Specific Configurations

Classical technique emphasizes pharyngeal expansion producing the singer’s formant cluster that enables projection over orchestral accompaniment. The orchestra’s energy peak appears around 500 Hz while the singer’s formant peak occurs around 3000 Hz, enabling audibility through spectral differentiation.

Belting demonstrates contrasting articulatory strategies: a less elevated soft palate position (compared to classical technique), pharyngeal wall narrowing, laryngeal raising, and aryepiglottic narrowing. Importantly, voice scientists distinguish that “there is a significant difference between ‘narrowed’ and ‘constricted.’ Skillful CCM singing allows for a narrowing of the throat (pharynx) and rising of the larynx that do not lead to sensations of narrowness or constriction.”

Common Misconceptions

Misconception: “An open mouth equals an open throat”

Reality: A jaw that is too low actually places tension on the larynx, lowers the soft palate, and inhibits the effective closure of the vocal folds. The pharyngeal expansion associated with “open throat” involves internal configurations (larynx lowering, soft palate elevation, pharyngeal widening) that are distinct from visible mouth opening. Over-opening can cause depressed larynx with tongue bunching, blocking tube-space in the throat.

Misconception: “Singers can directly and precisely control faucial pillar position”

Reality: The extent of voluntary control over faucial pillar muscles remains actively debated. Anatomical constraints documented by Kuehn and Azzam—the small diameter of palatoglossus, large amount of connective tissue, and non-rigid attachment—suggest that voluntary control may be more limited than traditional pedagogy assumes. Research notes an “unreliable relationship between PG activity and tongue raising,” with function varying greatly across individuals, languages, phonetic contexts, and studies.

Misconception: “Faucial pillar positioning directly causes improved resonance”

Reality: A fundamental unresolved question concerns causality: are faucial pillar and pharyngeal changes a cause of improved resonance, or merely an effect of other adjustments such as larynx lowering and tongue positioning? Recent research proposes that the classical singer’s facial expression may indirectly control pharyngeal space through breathing and smelling-related connections rather than direct faucial pillar manipulation (2018 study on nasal musculature).

Related Terms

Also known as: Tonsillar Pillars, Palatine Arches, Pillars of Fauces

See also: Oropharyngeal Isthmus (the space bounded by the pillars), Soft Palate (velum, works in coordination with pillars), Singer’s Formant (acoustic phenomenon enabled by pharyngeal expansion)

References

Echternach, Matthias, Fabian Burk, Michael Burdumy, Louisa Traser, and Bernhard Richter. 2016. “Morphometric Differences of Vocal Tract Articulators in Different Loudness Conditions in Singing.” PLoS ONE 11(4): e0153792. https://doi.org/10.1371/journal.pone.0153792.

Gick, Bryan, Peter Anderson, Hui Chen, Chenhao Chiu, Ho Beom Kwon, Ian Stavness, Ling Tsou, and Sidney Fels. 2014. “Speech Function of the Oropharyngeal Isthmus: A Modeling Study.” Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization 2(4): 217-222. https://doi.org/10.1080/21681163.2013.851627. 

Howard, David M. 2009. “Acoustics of the Trained versus Untrained Singing Voice.” Current Opinion in Otolaryngology & Head and Neck Surgery 17(3): 155-159. https://doi.org/10.1097/MOO.0b013e32832af11b.

Kuehn, David P., and Nabih A. Azzam. 1978. “Anatomical Characteristics of Palatoglossus and the Anterior Faucial Pillar.” Cleft Palate Journal 15(4): 349-359. 

Lee, Sang Hyuk, Hee Jung Kwon, Hyun Jung Choi, Nam Hee Lee, Soon Jae Lee, and Sung Min Jin. 2008. “The Singer’s Formant and Speaker’s Ring Resonance: A Long-Term Average Spectrum Analysis.” Clinical and Experimental Otorhinolaryngology 1(2): 92-96. https://doi.org/10.3342/ceo.2008.1.2.92. 

Mainka, Alexander, Anton Poznyakovskiy, Ivan Platzek, Mario Fleischer, Johan Sundberg, and Dirk Mürbe. 2015. “Lower Vocal Tract Morphologic Adjustments Are Relevant for Voice Timbre in Singing.” PLoS ONE 10(7): e0132241. https://doi.org/10.1371/journal.pone.0132241.

Mitchell, Helen F., and Dianna T. Kenny. 2003. “Open Throat: Acoustic and Perceptual Support for Pedagogic Practice.” Logopedics Phoniatrics Vocology 28(4): 151-162. https://doi.org/10.1080/14015430310018856. 

Mitchell, Helen F., and Dianna T. Kenny. 2004. “The Impact of ‘Open Throat’ Technique on Vibrato Rate, Extent and Onset in Classical Singing.” Logopedics Phoniatrics Vocology 29(4): 171-182. https://doi.org/10.1080/14015430410001033. 

Sundberg, Johan. 1974. “Articulatory Interpretation of the ‘Singing Formant.'” Journal of the Acoustical Society of America 55(4): 838-844. https://doi.org/10.1121/1.1914609.