Some differences between clicks and labio-velars

Abstract

Click consonants and labio-velar consonants are commonly grouped together, as complex segments – consonants having two simultaneous articulations in different places. While this grouping makes intuitive sense, it is not adequately supported. Complex segments appear to be unattested except for clicks and labio-velars; they are not an independently motivated class of sounds. A careful review of the facts reported in previous work reveals that the phonetic and phonological similarities between clicks and labio-velars are less significant than is commonly assumed. The conclusion of this paper is that unifying clicks and labio-velars as a natural class of complex stops is not empirically justified, and does not help explain the properties of either one.