23.3. Consonants

Consonants are classified with base on:

• Manner of articulation is how air escapes from the vocal tract when the consonant sound is made. Manners include stops, fricatives, africates, laterals and nasals. 

• Place of articulation is where in the vocal tract the obstruction of the consonant occurs, and which speech organs are involved. Places include bilabial (both lips), alveolar (tongue against the gum ridge), and velar (tongue against soft palate).

While manner and place of articulation form the main features used to categorize consonants, several other features are also considered in finer analyses:

• Phonation of a consonant is how the vocal cords vibrate during the articulation. When the vocal cords vibrate fully, the consonant is called voiced. When they do not vibrate at all, it is voiceless. 

• Voice onset time (VOT) indicates the timing of the interruption in relation to the onset of vocal fold vibration.

• Airstream mechanism is how the air moving through the vocal tract is powered. Most languages have exclusively pulmonic egressive consonants, which use the lungs and diaphragm, but ejectives, clicks, and implosives use different mechanisms.

• Length is how long the obstruction of a consonant lasts. This feature is borderline distinctive in English, as in "wholly" [hoʊlli] vs. "holy" [hoʊli], but it can be more distinctive in other languages.

Manners of articulation

The main manners of articulation include:

• Stop. Involves momentary blocking of airflow the oral vocal tract, and no nasal air flow. Examples include English p t and b. All languages have stops.

• Nasal.  Air passes through the nose. The shape and position of the tongue determine the resonant cavity that gives different nasals their characteristic sounds. Examples include English m, n. Nearly all languages have nasals.

• Fricative. There is continuous frication (turbulent and noisy airflow) at the place of articulation. Examples include English f, s, v and z. Most languages have fricatives. Indigenous Australian languages are almost completely devoid of fricatives of any kind.

• Sibilant. A type of fricative where the airflow is guided by a groove in the tongue toward the teeth, creating a high-pitched and very distinctive sound. These are by far the most common fricatives and include English s and z.

• Lateral fricative. A rare type of fricative, where the frication occurs on one or both sides of the edge of the tongue. The "ll" of Welsh is a lateral fricative.

• Affricate. Begins with a stop and continues as a fricative. The English letters ch and j are affricates. Affricates are common but less common than fricatives.

• Flap. Often called a tap, it is a momentary closure of the oral cavity. The "tt" of "utter" is a flap in North American English. 

• Trill. The articulator (usually the tip of the tongue) is vibrated by the airstream. The double "r" of Spanish "perro" is a trill.

• Approximant. There is very little constriction of the airflow. Examples include English w and r. 

• Lateral. Also called lateral approximant, this is pronounced with the sides of the tongue. English l is a lateral.

Places of articulation

The passive place of articulation is the place on the more stationary part of the vocal tract where the articulation occurs and can be anywhere from the lips, upper teeth, gums, or roof of the mouth to the back of the throat. The articulatory gesture of the active place of articulation involves the more mobile part of the vocal tract, typically some part of the tongue or lips.

With respect to the place of articulation, consonants are classified within the following major groups:

• Bilabial. Produced with both lips. Ex: b, m, and p.

• Labiodental. f and v are articulated by placing the upper teeth against the lower lip.

• Interdental. "th" as in think or as in the are pronounced by inserting the tip of the tongue between the teeth.

• Alveolar. t, d, n, s, z, l, and r are produced with the tongue is raised towards the alveolar ridge. The tip of the tongue may touch the ridge (t, d, n), or the tip may be lowered so that air escapes over it (s, z). For l, the middle of the tongue is raised while air escapes around its sides. For r, the tip of tongue is curled back behind the alveolar ridge, or bunched up behind the ridge and the air escapes through the central part of the mouth.

• Palatal. j is produced by raising the front part of the tongue to the palate.

• Velar. k and g are produced by raising the back of the tongue to the soft palate or the soft palate.

• Uvular. Some sounds are produced by raising the back of the tongue to the uvula. The 'r' in French and German may be an uvular trill. These do not normally occur in English.

• Glottal. h results from the flow of air coming from an open glottis, past the tongue and lips as they prepare to pronounce the vowel that follows h. 

Summary

Consonants involve blocking or restricting the airflow through various manners of articulation and doing so at various places of articulation. The various possible combinations between manners and places of articulation originate the great variety of consonant sound observed in the multitude of languages spoken around the world.

Keywords

Manner of articulation, place of articulation, voice onset time, airstream mechanisms, stop, nasal, fricative, sibilant, lateral fricative, africate, flap, trill, approximant, lateral, bilabial consonant, labiodental consonant, interdental consonant, alveolar consonant, palatal consonants, velar consonant, uvular consonant, glottal consonant.

Figure credits

Figure 1 by created by User:ish shwar (original .png deleted), .svg by Rohieb - sagittal section image based on Minifie et al. (1973:); articulation places are from Catford (1977), CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1771968