Topic-094: Summary of the Airstream Mechanisms There are three possible mechanisms involved inhuman speech production. The most common one is the moving of air by compression of the lungs so that the air is expelled through the vocal tract this is called a pulmonic airstream - usually an egressive pulmonic one, but occasionally speech is produced while breathing in. The second one is the glottalic (produced by the larynx with closed vocal folds - it is moved up and down like the plunger of a bicycle pump) and the last one is called velaric where the back of the tongue is pressed against the soft palate or velum - making an airtight seal, and then drawn backwards or forwards to produce an airstream). The ingressive glottalic consonants (often called implosives) and egressive ones (ejectives) are found in many non-European languages. On the other hand, click sounds (ingressive velaric) are much rarer, but occur in a number of southern African languages such as Nàmá, Xhosa (or Hausa) and Zulu. Speakers of other languages including English use click sounds for non-linguistic communication as in the case of the “tut-tut” (equal to the American “tsk- tsk”) known as the sounds of disapproval.
