Articulatory phonetics

Articulatory phoneticians explain how humans produce speech sounds via the interaction of different physiological structures.

However, to vary the sound quality in a way useful for speaking, two speech organs normally move towards each other to contact each other to create an obstruction that shapes the air in a particular fashion.

The atmosphere external to the articulatory stem may also be considered an air cavity whose potential connecting points with respect to the body are the nostrils and the lips.

The three pistons present in the articulatory system are the larynx, the tongue body, and the physiological structures used to manipulate lung volume (in particular, the floor and the walls of the chest).

To produce sounds that people can interpret as spoken words, the movement of air must pass through the vocal folds, up through the throat and, into the mouth or nose to then leave the body.

The respiratory organs used to create and modify airflow are divided into three regions: the vocal tract (supralaryngeal), the larynx, and the subglottal system.

In pulmonic sounds, the airstream is produced by the lungs in the subglottal system and passes through the larynx and vocal tract.

Constrictions can be made in several parts of the vocal tract, broadly classified into coronal, dorsal and radical places of articulation.

To account for this, more detailed places of articulation are needed based upon the area of the mouth in which the constriction occurs.

[13][14] They exist in a number of languages indigenous to Vanuatu such as Tangoa, though early descriptions referred to them as apical-labial consonants.

The coronal places of articulation represent the areas of the mouth where the tongue contacts or makes a constriction, and include dental, alveolar, and post-alveolar locations.

In this way, retroflex articulations can occur in several different locations on the roof of the mouth including alveolar, post-alveolar, and palatal regions.

If the underside of the tongue tip makes contact with the roof of the mouth, it is sub-apical though apical post-alveolar sounds are also described as retroflex.

[23] Articulations taking place just behind the alveolar ridge, known as post-alveolar consonants, have been referred to using a number of different terms.

[16] Because of individual anatomical variation, the precise articulation of palato-alveolar stops (and coronals in general) can vary widely within a speech community.

These variations are typically divided into front, central, and back velars in parallel with the vowel space.

[37] Fricatives are consonants where the airstream is made turbulent by partially, but not completely, obstructing part of the vocal tract.

[36] Sibilants are a special type of fricative where the turbulent airstream is directed towards the teeth,[38] creating a high-pitched hissing sound.

[42] The stricture is formed in such a way that the airstream causes a repeating pattern of opening and closing of the soft articulator(s).

[46] Clicks are stops in which tongue movement causes air to be sucked in the mouth, this is referred to as a velaric airstream.

Except in some marginal cases, the vocal tract is open, so that the airstream is able to escape without generating fricative noise.

Variation in vowel quality is produced by means of the following articulatory structures: The glottis is the opening between the vocal folds located in the larynx.

Vowels may be made pharyngealized (also epiglottalized, sphincteric or strident) by means of a retraction of the tongue root.

Since pressure is a force applied to a surface area by definition and a force is the product of mass and acceleration according to Newton's Second Law of Motion, the pressure inequality will be resolved by having part of the mass in air molecules found in the subglottal cavity move to the supraglottal cavity.

Similarly, in an ejective consonant with a glottalic airstream mechanism, the lips or the tongue (i.e., the buccal or lingual valve) are initially closed and the closed glottis (the laryngeal piston) is raised decreasing the oral cavity volume behind the valve closure and increasing the pressure compared to the volume and pressure at a resting state.

A periodic sound source is vocal fold vibration produced at the glottis found in vowels and voiced consonants.

A less common periodic sound source is the vibration of an oral articulator like the tongue found in alveolar trills.

Aperiodic sound sources are the turbulent noise of fricative consonants and the short-noise burst of plosive releases produced in the oral cavity.

Voicing is a common period sound source in spoken language and is related to how closely the vocal cords are placed together.

In order to collect EPG data, the speaker is fitted with a special prosthetic palate, which contains a number of electrodes.