click, Click Here to see full-size tableClick notationin phonetics, a suction sound made in the mouth. Click sounds occur in a number of African languages and are often used as interjections in other languages—e.g., the sound of disapproval represented in English by tsk, tsk. That sound is an example of a dental click; to make it, the back of the tongue contacts the soft palate and the sides and tip of the tongue touch the teeth. The click noise occurs when the tip of the tongue is lowered. Other click sounds differ in the positions of the tip and blade of the tongue and in the manner of the release of air into the mouth cavity.

Clicks are a regular part of the consonant system in the Khoisan languages (sometimes called click languages) of such peoples as the Nama and !Xóõ. Linguists have distinguished five distinctive sounds, including dental clicks (as described above), lateral clicks (like the clucking sound made to horses), alveolar clicks (in which the tip of the tongue is on the ridge behind the upper teeth), postalveolar clicks, and, in some dialects, bilabial clicks (making the sound of a kiss), as well as a number of variants. Nguni languages of southern Africa, which include Zulu and Xhosa, are believed to have borrowed their clicks from Khoisan languages. See also Khoisan languages, which contains several audio clips.

click languages, a group of languages found only in Africa in which clicks function as normal consonants. The sole report outside Africa of a language using clicks involves the special case of Damin, a ritual vocabulary of the Lardil of northern Queensland, Australia.

While clicks are an extensive and original feature of the Khoisan languages, they have spread through linguistic contacts into a number of other languages of the Bantu and Cushitic groups. These languages are therefore full-fledged click languages but derivatively so. In all click languages, clicks form only a portion—though sometimes the main portion—of the total number of consonants of the language. Very distinctive sounds, clicks are articulated in the mouth by a suction mechanism that produces either a sharp popping or smacking sound between the tongue and the roof of the mouth or a sucking sound between the lips (the kiss click) or teeth or at the side of the mouth. Most Khoisan languages use four clicking sounds; the Southern languages use a fifth, the “kiss” click, as well. Gciriku and Yei, which are Bantu languages of Botswana and Namibia, have incorporated the four-click Khoisan system, but Zulu and Xhosa (also Bantu languages) have incorporated only three clicks. Dahalo, a Cushitic language of Kenya, uses only one click. In some Khoisan languages two of the clicks have been gradually replaced with acoustically similar nonclick consonants, which in effect has produced a two-click system.

Clicks are used extensively in the vocabulary of Khoisan languages, and they are the initial sounds in approximately 70 percent of the words. This lends a dramatic effect to running speech. Clicks are extremely salient sounds perceptually and therefore are ideally adapted to transmitting a language. Their exotic nature and uniqueness has invited speculation that they may be associated with special meanings, but this is not the case.

Anthony Traill