Why are clicks so exclusive ?

Clicks occur abundantly in the languages of southern Africa, but are not found anywhere else. This is unexpected since the clicks seem to be both auditorily salient and easy to produce. This paper suggests that the reason for the areal skewness of clicks lies in the African phonetictypological environment rather than in production or perception constraints. In particular, clicks are limited to Africa because they are likely to emerge historically only in the presence of certain phonetic preconditions, which are rare from a world-wide perspective but characteristic of the African languages. In theory, once clicks have made their appearance, they should, by virtue of both their auditory saliency and ease of production, remain in the phonetic repertoire and be resistant to change.