showing a typical classification of sounds (in IPA) and their
manners of articulation and distinctive features|class=skin-invert-image This section lists and describes distinctive features in linguistics.
Major class Major class features: The features that represent the major classes of sounds. • [+/− syllabic] Syllabic segments may function as the
nucleus of a
syllable, while their counterparts, the [−syll] segments, may not. Except in the case of
syllabic consonants, [+syllabic] designates all
vowels, while [−syllabic] designates all
consonants (including
glides). • [+/− consonantal] Consonantal segments are produced with an audible constriction in the
vocal tract, such as
obstruents,
nasals,
liquids, and
trills. Vowels,
glides and laryngeal segments are not consonantal. • [+/− approximant] Approximant segments include vowels,
glides, and
liquids while excluding
nasals and
obstruents. • [+/− sonorant] This feature describes the type of oral constriction that can occur in the vocal tract. [+son] designates the
vowels and
sonorant consonants (namely
glides,
liquids, and
nasals) that are produced without an imbalance of air pressure in the vocal tract that might cause turbulence. [−son] describes the
obstruents, articulated with a noticeable turbulence caused by an imbalance of air pressure in the vocal tract.
Laryngeal Laryngeal features: The features that specify the glottal states of sounds. • [+/− voice] This feature indicates whether vibration of the
vocal folds occurs with the articulation of the segment. • [+/− spread glottis] Used to indicate the
aspiration of a segment, this feature denotes the openness of the glottis. For [+sg], the vocal folds are spread apart widely enough for friction to occur; for [−sg], there is not the same friction-inducing spreading. • [+/− constricted glottis] The constricted glottis feature denotes the degree of closure of the glottis. [+cg] implies that the vocal folds are held closely together, enough so that air cannot pass through momentarily, while [−cg] implies the opposite. [+cg] sounds include
glottalized,
ejective and
implosive consonants, as well as the
glottal stop.
Manner Manner features: The features that specify the
manner of articulation. • [+/−
continuant] This feature describes the passage of air through the vocal tract. [+cont] segments are produced without any significant obstruction in the tract, allowing air to pass through in a continuous stream. [−cont] segments, on the other hand, have such an obstruction, and so occlude the air flow at some point of articulation. • [+/−
nasal] This feature describes the position of the
velum. [+nas] segments are produced by lowering the velum so that air can pass through the
nasal tract. [−nas] segments conversely are produced with a raised velum, blocking the passage of air from the nasal tract and shunting it to the oral tract. • [+/− strident] The strident feature applies to obstruents only and refers to a type of friction that is noisier than usual. This is caused by high energy
white noise. • [+/−
lateral] This feature designates the shape and positioning of the
tongue with respect to the oral tract. [+lat] segments are produced as the center of the tongue rises to contact the roof of the mouth, thereby blocking air from flowing centrally through the oral tract and instead forcing more lateral flow along the lowered side(s) of the tongue. • [+/− delayed release] This feature distinguishes
stops from
affricates. Affricates are designated [+del rel]
Place Place features: The features that specify the
place of articulation. • [
LABIAL ] Labial segments are articulated with the lips. As consonants, these include
bilabial and
labiodental consonants. • [+/− round]: [+round] are produced with lip rounding, while [−round] are not. • [
CORONAL ] Coronal sounds are articulated with the
tip and/or
blade of the tongue. These include a large number of consonants, which can be made with the tip, blade or underside of the tongue (
apical,
laminal, or
subapical consonant, respectively), making contact with the upper lip (
linguolabial), between the teeth (
interdental), with the back of the teeth (
dental), with the
alveolar ridge (
alveolar), behind the alveolar ridge (
postalveolar), or on or in front of the
hard palate (
(pre)palatal). With
postalveolar sibilants, additional tongue shapes need to be distinguished, i.e. "domed" or slightly palatalized ("hushing" or "palato-alveolar"),
palatalized (
alveolopalatal), and "closed" ("hissing-hushing"). • [+/− anterior]: Anterior segments are articulated with the tip or blade of the tongue at or in front of the alveolar ridge. Dental consonants are [+ant], postalveolar and retroflex ones are [−ant]. • [+/− distributed]: For [+dist] segments the tongue is extended for some distance in the mouth. In other words, laminal dental and postalveolar consonants are marked as [+dist] (with wider or more distributed constriction), while apical alveolar and retroflex consonants are [−dist] (with narrower or more concentrated constriction). • [
DORSAL ] Dorsal sounds are articulated by raising the dorsum of the tongue. All vowels are dorsal sounds. Dorsal consonants include
palatal,
velar and
uvular consonants. • [+/− high]: [+high] segments raise the dorsum close to the
palate. [−high] segments do not. • [+/− low]: [+low] segments bunch the dorsum to a position low in the mouth. • [+/− back]: [+back] segments are produced with the tongue dorsum bunched and retracted slightly to the back of the mouth. [−back] segments are bunched and extended slightly forward. • [+/− tense]: This feature (mainly) applies to the position of the root of the tongue when articulating vowels. [+tense] vowels have an advanced tongue root. In fact, this feature is often referred to as
advanced tongue root (ATR), although there is a debate on whether tense and ATR are the same or different features. • [
RADICAL ] Radical sounds are articulated with the root of the tongue. These include
epiglottal consonants. • [+/− advanced tongue root]: [+ATR] segments advance the root of the tongue. • [+/− retracted tongue root]: [+RTR] segments bunch the root of the tongue towards the pharyngeal wall and activate the
pharyngeal constrictor muscles • [
GLOTTAL ] Purely glottal sounds do not involve the tongue at all. These are the
glottal consonants.
Vowel space Vowels are distinguished by • [+/− back] (
back vowels) • [+/− high] (
close vowels) • [+/− low] (
low vowels) • [+/− tense] (
tense vowels) However, laryngoscopic studies suggest these features • [+/− front] (
front vowels) • [+/− raised] (
raised vowels) • [+/− retracted] (
retracted vowels) • [+/− round] (
round vowels) ==Jakobsonian system==