Descriptive Grammar of English WSJO 2010/2011 – Year 2
1.
The airstream mechanism is the method by which airflow is initiated in the vocal tract:
• the organ which is responsible for generating the airstream is called the initiator
• there are three initiators used in the production of sounds:
− the diaphragm and the lungs: pulmonic airstream mechanism
− the glottis and the larynx – glottalic airstream mechanism
•
− the tongue – velaric airstream mechanism each initiator can act by increasing pressure in the airstream or reducing it with suction – these changes in pressure are inseparably connected with the direction of airflow; thus we distinguish:
− egressive (outward) airflow
•
− ingressive (inward) airflow each of the mechanisms mentioned above can be (at least theoretically) egressive or ingressive, for example, the most common mechanism is the pulmonic egressive airstream mechanism
2.
Pulmonic airstream mechanism :
• pulmonic egressive – the air is pushed out of the lungs by the ribs and the diaphragm
− the normal mode and the basis of all normal speech in all languages, and many languages (including English and
Polish) use it exclusively
− easy to control and requires less articulatory effort than the others
• pulmonic ingressive uses exhalation as a form of airstream initiation – to do this, we dilate the lungs, thus lowering the pressure within them and so sucking air down the trachea and into the lungs (no language uses it as a distinctive feature of particular speech sounds during normal articulation)
3.
Glottalic airstream mechanism :
• glottalic egressive (EJECTIVES) – the air column is pushed upward by the glottis (see Figure 1)
Figure 1. The sequence of events in the production of an ejective velar stop (after
Ladefoged 2001:114)
− since the glottis must be tightly closed the sounds we produce this way are voiceless
− ejectives are common only in some parts of the world: the indigenous languages of Americas (Quechua, Navaho) and Caucasus (Georgian, Armenian)
• glottalic ingressive (IMPLOSIVES) – the glottis is moved down so as to enlarge the pharyngeal cavity and produce suction (see Figure 2)

Descriptive Grammar of English WSJO 2010/2011 – Year 2
Figure 2. The sequence of events in the production of a bilabial implosive
(after Ladefoged 2001:117).
− because of the difficulty of maintaining a tightly closed glottis during the downward movement of the larynx, some lung air manages to pass through the glottis and causes involuntary phonation
− implosives can be found in languages of Africa (e.g. Hausa)
4.
Velaric airstream mechanism :
• velaric ingressive (CLICKS) – the air in the mouth is rarefied by a downward movement of the tongue (see Figure 3)
Figure 3. The sequence of events in the production of a dental click (after
Ladefoged 2001:120).
− double closure: the back of the tongue against the velum and the front parts of the tongue against the teeth
− the tongue movement is a very important factor – the release of the front closure causes the outer air to be sucked in, accompanied by a characteristic click sound
− clicks are found in rather few languages: Khoisan languages in southern Africa (Hottentot), Bantu languages
(Zulu and Xhosa)
• velaric egressive – it is possible to cause the airstream to flow outward by raising the tongue and squeezing the contained body of air, but this possibility is not actually used in any known language