Some Languages Have Click Consonants

While many people use clicking sounds for expressions like the "tsk-tsk" of disapproval or the sound to spur on a horse, these are integral consonants in dozens of languages across southern and eastern Africa. Unlike most speech sounds, which are pulmonic and formed by pushing air from the lungs, clicks are created using a velaric airstream. This involves the tongue (Review) making two closures in the mouth, creating a pocket of air that is then rarefied by a sucking motion; releasing the forward closure produces the distinct popping sound. There are five primary types of clicks recognized by the International Phonetic Alphabet, including bilabial (lip-smacking), dental, and lateral (side of the mouth) sounds.

These unique consonants are a hallmark feature of the Khoisan language families of southern Africa. Through linguistic contact and intermarriage over centuries, clicks were also adopted by neighboring Bantu languages, such as Zulu and Xhosa, as well as a few languages in East Africa like Sandawe and Hadza. The precise origin of clicks in human language is still a mystery, though some researchers speculate they may be an ancient feature, while others believe they evolved from clusters of non-click consonants.

The complexity of click usage varies greatly, from just a few in some languages to a vast inventory in others. In the Taa language, spoken in Botswana and Namibia, clicks are foundational, with some analyses counting over 100 distinct click consonants. In Taa, it is estimated that over 70% of all words begin with one of these click sounds, demonstrating how fundamental they are to the language's phonology and vocabulary.