Differences in airstream and posterior place of articulation among Nǀuu clicks

This paper describes the consonant inventory of the endangered southern African language Nǀuu. Our novel approach to segment classification accounts for all 73 Nǀuu consonants with just four phonetic dimensions (place, manner, phonation, airstream) and does away with the phonetically empty category click accompaniment . We provide ultrasound data showing that the posterior constrictions in clicks are not produced at the ‘velar’ place of articulation, and that posterior place differs with anterior place. We therefore argue for a terminological shift from velaric to lingual airstream mechanism. Our data also show that the posterior place of articulation is the same in Nǀuu's five lingual ([⊙ ǀ ǃ ǁ ǂ]) and linguo-pulmonic ([ ]) stops. We argue that the difference between these segment classes is best captured in terms of airstream, not place. Plain clicks use only the lingual airstream, while linguo-pulmonic segments are airstream contours, in which the transition to the pulmonic airstream occurs within the segment rather than at its boundary. Our evidence suggests that the contrast between ‘velar’ and ‘uvular’ clicks proposed for the related language ǃXóõ is likely also one of airstream and that a contrast solely in terms of posterior place would be articulatorily impossible.