The airstream mechanism is lingual ingressive (also known as velaric ingressive), which means a pocket of air trapped between two closures is rarefied by a "sucking" action of the tongue, rather than being moved by the glottis or the lungs/diaphragm. The release of the forward closure produces the "click" sound. Voiced and nasal clicks have a simultaneous pulmonic egressive airstream.
Its phonation is voiceless, unaspirated, and unglottalized, which means it is produced without vibration or constriction of the vocal cords, and any following vowel starts without significant delay.
It is an oral consonant, which means air is allowed to escape through the mouth only.
Because the sound is not produced with airflow over the tongue, the central–lateral dichotomy does not apply.
Occurrence[]
Tenuis bilabial clicks are only known to occur in the Tuu and Kx'a families of southern Africa.
