Click consonant

Template:Manner of articulation Clicks are speech sounds such as English tsk! tsk! used to express disapproval, or the tchick! used to spur on a horse. In many languages of southern Africa, and in three languages of East Africa, they are ordinary consonants, found for example in the name of the language Xhosa. Clicks are best known in the West through the 1980 film The Gods Must Be Crazy. In 2003 clicks were in the news with an announcement that the original human language may have had clicks, but most linguists agree that this is unverifiable.

Technically, clicks are obstruents articulated with two closures (points of contact) in the mouth, one forward and one at the back. The pocket of air enclosed between is rarefied by a sucking action of the tongue. (That is, clicks have a velaric/lingual ingressive airstream mechanism.) The forward closure is then released, producing what may be the loudest consonants in the language, although in some languages such as Hadza, clicks can be more subtle and may even be mistaken for ejective stops.

Languages with clicks

Clicks occur in all three Khoisan language families of southern Africa, where they may be the most numerous consonants. To a lesser extent they are found in several neighbouring Bantu languages which borrowed them from Khoisan. The most famous of these are the languages of the Nguni cluster (Zulu, Xhosa, Swazi, Phuthi, Ndebele, and the Zulu-based pidgin Fanagalo); the other Bantu click languages are Sesotho, Yeyi of Botswana, and the Mbukushu, Kwangali, and Gciriku languages of the Caprivi Strip.

There are three small languages in East Africa which use clicks: Sandawe and Hadza of Tanzania, as well as Dahalo, an endangered South Cushitic language of Kenya which has clicks in only a few dozen words. It is thought these may remain from an episode of language shift.

The only non-African language known to employ clicks as regular speech sounds is Damin, a ritual code used by speakers of Lardil in Australia. One of the clicks in Damin is actually an egressive click, using the tongue to compress the air in the mouth for an outward (egressive) "spurt".

The Southern African Khoisan languages only utilize root-initial clicks. Hadza, Sandawe, and several of the Bantu languages also allow syllable-initial clicks within roots, but in no known language does a click close a syllable or end a word.

English and many other languages may use clicks in interjections, such as the dental "tsk-tsk" sound used to express disapproval, or the lateral tchick used with horses. In Ningdu Chinese, flapped nasal clicks are used in nursery rhymes, and in Persian a click accompanied by tipping the head upwards signifies "no". Clicks will occasionally turn up elsewhere, as in the special registers twins sometimes develop with each other.

Types of clicks

As noted above, clicks necessarily involve at least two closures: an anterior articulation which has traditionally been represented by the special click symbol in the IPA, and a posterior articulation which has been traditionally described as oral or nasal, voiced or voiceless, etc. (It's quite easy to pronounce a nasal click, since while maintaining the double oral closure you're free to breathe through the nose. In fact, these are easier to pronounce for many people than oral clicks.) The literature also describes a contrast between velar and uvular rear articulations for some languages. However, recent work has shown that for languages which make this distinction, all clicks have a uvular, or even pharyngeal, rear closure, and that the clicks explicitly described as uvular are in fact click-pulmonic consonant clusters/contours with two release bursts, the click itself, and then a uvular consonant. In the case of "velar" clicks in these languages, on the other hand, there is only a single release burst, that of the forward click release, and the release of the rear articulation isn't audible.

Nonetheless, in most of the literature the stated place of the click is the anterior articulation (called the release or influx), while the manner is ascribed to the posterior articulation (called the accompaniment or efflux), as in a "nasal dental click".

There are numerous manners of clicks, some of them quite daunting. These include what has been described as voiceless, voiced, aspirate, breathy voiced, nasal, voiceless nasal, breathy voiced nasal, glottalized, voiceless nasal glottalized, affricate, ejective affricate, prevoiced, prenasalized, and others as well, including extremely complex combinations such as a voiced velar click followed by voiceless affricated ejective, [gǃkx’], and a velar ejective click followed by uvular ejective, [kǃ’q’] (Ladefoged and Maddieson, 1996). However, some of these may be consonant clusters rather than individual segments.

The size of click inventories ranges from as few as four for the Dahalo language of Kenya, to dozens in the Juu and Tuu languages (Northern and Southern Khoisan), and perhaps over a hundred, depending on how they're analysed, in ǃXóõ (Ladefoged and Maddieson, 1996). In the latter language, over 70% of words begin with a click.

Clicks appear more stop-like or more affricate-like depending on their place of articulation: In southern Africa, clicks involving an apical alveolar or laminal postalveolar closure are acoustically abrupt and sharp, like stops, while bilabial, dental, and lateral clicks typically have longer and acoustically noisier releases that are more like affricates. In East Africa, however, the alveolar clicks tend to be flapped, while the lateral clicks tend to be more sharp and abrupt.

Transcription

The five click releases with dedicated symbols in the International Phonetic Alphabet (IPA) are bilabial ʘ, dental ǀ, palato-alveolar or "palatal" ǂ, (post)alveolar or "retroflex" ǃ, and alveolar lateral ǁ. The retroflex and palatal releases are "abrupt"; that is, they are sharp popping sounds with little frication (turbulent airflow). The bilabial, dental, and lateral releases, on the other hand, are "noisy": they are longer, lip- or tooth-sucking sounds with turbulent airflow, and are sometimes called affricates. (This applies to the forward articulation; both may also have either an affricate or non-affricate rear articulation as well.) The apical releases, ǃ and ǁ, are sometimes called "grave", because their pitch is dominated by low frequencies; while the laminal releases, ǀ and ǂ, are sometimes called "acute", because they are dominated by high frequencies. (At least in the Nǀu language, this is associated with a difference in the placement of the rear articulation: "grave" clicks are uvular, whereas "acute" clicks are pharyngeal.) Thus the alveolar click /ǃ/ sounds something like a cork pulled from a bottle (a low-pitch pop), at least in Xhosa; while the dental click /ǀ/ is like English tsk! tsk!, a high-pitched sucking on the incisors. The lateral clicks are pronounced by sucking on the molars of one or both sides. The bilabial click /ʘ/ is different from what many people associate with a kiss: the lips are pressed more-or-less flat together, as they are for a [p] or an [m], not rounded as they are for a [w].

The IPA came up with a set of Latin-based symbols for these sounds, but they were never much used, and were eventually given up for the Khoisanist symbols:

symbol	bilabial	dental	alveolar	palatal	lateral
Khoisanist	ʘ	ǀ	ǃ	ǂ	ǁ
old IPA	q̢	ʇ	ʗ	°	ʖ
Zulu		c	q		x

There are a few less well attested articulations, such as a noisy laminal denti-alveolar lateral release (<Ⅲ> [triple pipe] in an ad hoc transcription), which contrasts with an apical postalveolar lateral in Mangetti Dune ǃKung; an abrupt sub-apical retroflex release <‼> in Angolan ǃKung; and a "slapped" alveolar click <ǃ¡> in Hadza and Sandawe, where the tongue slaps the bottom of the mouth after the release. (These distinctions may suffice for the Damin releases as well.) However, the Khoisan languages are poorly attested, and it is quite possible that, as they become better described, more click releases will be found.

Typically when a click consonant is transcribed, two symbols are used, one for each articulation, connected with a tie bar. This is because a click such as [ŋ͡ǂ] has been traditionally been analysed as a nasal velar rear articulation [ŋ] pronounced simultaneously with the forward ingressive release [ǂ]. The symbols may be written in either order, depending on the analysis. However, a tie bar is not often used in practice, and when the manner is a simple [k], it will often be omitted as well. That is, <ǂ> = <kǂ> = <ǂk> = <k͡ǂ> = <ǂ͡k>.

The manner of a click is generally written before the release: <ŋ͡ǂ> or <ŋǂ>, and this is preferred by the IPA. However, many Khoisanists prefer to write the manner second: <ǂ͡ŋ> or <ǂŋ>. This is because any diacritics which follow belong to the manner rather than to the forward release, and they are more easily understood when they are made diacritics of the manner. Regardless, elements which do not overlap with the release are always written according to their temporal order: Prenasalization is always written first in <ŋɡ͡ǂ> = <ŋǂ͡ɡ>, and the second ejective is always written second in <k͡ǂ’q’> = <ǂ͡k’q’>.

While the SAMPA encoding for IPA into ASCII doesn't have symbols for transcribing clicks, the proposed X-SAMPA standard does: O\, |\, |\|\, =\, and !. Some instead suggest ||\, #\ or "\ for the alveolar lateral click. The Kirshenbaum system uses a different method: clicks are denoted by digraphs, with the click symbol (always "!") added to the stop homorganic to the release, but with the manner of the accompaniment. For example, /t!/ is a voiceless dental click, and /m!/ is a nasal bilabial click. (This transcription is used in the literature on Damin.) However, the International Phonetic Association recommends using the IPA symbols in Unicode, or using the number codes which they have assigned to each symbol.

Places of articulation

These are often called click types, releases, or influxes. There are seven or eight known releases, not counting slapped or egressive clicks. These are bilabial affricated ʘ, or "bilabial"; laminal denti-alveolar affricated ǀ, or "dental"; apical (post)alveolar plosive ǃ, or "alveolar"; laminal postalveolar (palato-alveolar) plosive ǂ, or "palatal"; subapical postalveolar (retroflex) ǃ˞ (in central Ju); and two lateral clicks, which in the only dialects known to distinguish them (northern Ju) are laminal denti-alveolar lateral ǁ̻ with a forward release (or sometimes a palatal click with a lateral release), and apical postalveolar lateral ǁ̺ with a rear release. There may be an additional palatal-like click, symbolized ǂǂ, in another Ju lect which is currently being investigated. Given the poor state of documentation of Khoisan languages, it is quite possible that additional releases will turn up. No language is known to contrast more than five releases.

Click release inventory	Languages
dental ǀ only	Dahalo
alveolar ǃ only	Sesotho
3 releases, ǀ, ǃ, ǁ	Sandawe, Hadza, Xhosa, Zulu	(in Hadza and sometimes Sandawe, ǃ is "slapped"; Hadza also has a single word with ʘ)
4 releases, ǀ, ǂ, ǃ, ǁ	Korana, Nama, Yeyi, Zhuǀ'hõasi (southeastern Ju)
4 releases, ǀ, ǂ, ǃ˞, ǁ	ǃKung (Grootfontein)
5 releases, ʘ, ǀ, ǂ, ǃ, ǁ	ǂHõã, Nǀu, ǀXam, ǃXóõ
5 releases, ǀ, ǂ, ǃ, ǁ̺, ǁ̪	ǃKung (Angola)
5 releases, ʘ, ʘ↑, ǀ, ǃ, ǃ˞	Damin

Names found in the literature

The terms for the click releases were originally developed by Bleek in 1911. Since then there has been some conflicting variation. Here are the terms used in some of the main references.

Click release	Bantu letters	Also known as:
ǀ dental	c	dental affricative/affricated/with friction; alveolar affricated; denti-alveolar; apico-lamino-dental; denti-pharyngeal
ǂ palatal		palato-alveolar; alveolar; alveolar instantaneous; denti-alveolar implosive; palato-pharyngeal
ǃ alveolar	q	cerebral; (post-) alveolar implosive; palato-alveolar; palato-alveolar instantaneous; palatal; palatal retroflex; apico-palatal; central alveo-uvular
ǁ lateral	x	lateral affricative/with friction; alveolar lateral affricated; post-alveolar lateral; lateral apico-alveo-palatal; lateral alveo-uvular

Manners of articulation

(Data is primarily from Ladefoged; see references at individual language articles.)

Click manners are often called click accompaniments or effluxes, but both terms are objected to on theoretical grounds.

There is a great variety of click manners, both simplex and complex, the latter variously analysed as consonant clusters or contours. With so few click languages, and so little study of them, it is also unclear to what extent clicks in different languages are equivalent. For example, the [ǃkˀ] of Nama, [ǃkˀ ~ ŋˀǃk] of Sandawe, and [ŋ̊ǃˀ ~ ŋǃkˀ] of Hadza may be essentially the same phoneme, as may [ǃk͡x’] and [ǃq͡χ’]; no one language distinguishes either set, and the differences in transcription may have more to do with the approach of the linguist than with actual differences in the sounds.

Some Khoisan languages are typologically unusual in allowing mixed voicing in non-click consonant clusters/contours, such as dt͡s’k͡x’, so it is not surprising that they would allow mixed voicing in clicks as well.

There is ongoing discussion as to which clicks are best analysed as consonant clusters. For example, some linguists feel that ejective clicks are not possible, and indeed in many Khoisan languages they appear to be clusters. However, in other languages, phonetic measurements have found that, although the ejective release follows the click release, it is the rear closure of the click that is ejective, not a subsequent consonant. (In Ladefoged's analysis in the table below, if there is only a single segment, this is indicated by a single non-subscript letter for the accompaniment.) This is one reason for analysing such clicks as airstream contours instead of clusters.

Of the languages illustrated below,

ǃXóõ and Nǀu are Tuu languages
ǂHoan and Juǀʼhõasi are ǂHoan-Juu languages
Korana, Nama, and Gǀui are Khoe languages

(all spoken primarily in Namibia and Botswana)

Sandawe and Hadza are language isolates spoken in Tanzania
Dahalo is a Cushitic language of Kenya
Xhosa is a Bantu language of South Africa
Damin was an initiation jargon in northern Australia.

The four Dahalo manners occur only with a dental release. Damin has only nasal clicks, but in addition has a voiceless unaspirated "spurt" that might be considered an egressive click. Three Sandawe clicks (*) conflate to prenasalized voiced [ŋǃg] between vowels. In other languages nasalization is variable, and may be best heard between vowels.

IPA	Manner	ǃXóõ	Nǀuu	ǂHoan	Zhuǀ’hõasi	Korana	Nama	Gǀui	Sandawe	Hadza	Dahalo	Xhosa	Damin
[ǃk]	Voiceless unaspirated velar plosive	•	•	•	•	•	•	•	• *	•		•
[ǃkʰ]	Aspirated velar plosive	•	•	•	•	•	•	•	• *	•		•
[ǃkˀ]	Voiceless unaspirated velar plosive and glottal stop	•			•	•	•
[ǃkˀ, ŋˀǃk]	Voiceless glottalized velar plosive (prenasalized between vowels)			•				•	•
[ŋ̊ǃˀ]	Voiceless velar nasal and glottal stop		•							•
[ǃg]	Voiced velar plosive	•	•	•	•			•	• *
[ǃgx, ǃg͡ɣ, ǃgʱ]	Voiced affricated velar plosive				•
[ǃgʱ]	Breathy-voiced velar plosive											•
[ǃŋ]	Voiced velar nasal	•	•	•	•	•	•	•	•	•	•	•	•
[ǃŋʷ]	Labialized voiced velar nasal										•
[ǃŋʱ]	Breathy-voiced velar nasal											•
[ǃŋ̊]	Voiceless velar nasal	•									•
[ǃŋ̊ʷ]	Labialized voiceless velar nasal										•
[ŋ̊ǃh]	Voiceless delayed-aspirated velar nasal		•	•	•	•	•	•
[ŋ̊↓ǃh]	Voiceless ingressive pulmonic nasal with delayed aspiration	•
[ʔǃŋ]	Preglottalized velar nasal	•		•
[ŋǃŋ̊ʰ]	Voiced velar nasal followed by voiceless aspirated velar nasal				•
[ǃq]	Voiceless unaspirated uvular plosive	•	•	•				•
[ǃqʰ]	Aspirated uvular plosive		•	•				•
[ǃk͡x]	Voiceless affricated velar plosive	•			•
[ǃq͡χ]	Voiceless affricated uvular plosive		•	•				•
[ǃq’]	Uvular ejective	•		•				•
[ǃk͡x’]	Affricated velar ejective				•	•
[ǃq͡χ’]	Affricated uvular ejective		•	•				•
[ǃk’q’, ǃk’k͡x’]	Voiceless velar ejective, followed by uvular ejective	•
[ǃgh, ǃgkʰ]	Voiced velar plosive followed by aspiration	•			•
[ǃgk͡x]	Voiced velar plosive followed by voiceless velar fricative	•
[ǃgk͡x’]	Voiced velar plosive followed by voiceless affricated ejective				•
[ǃgq’, ǃgk͡x’]	Voiced velar plosive, followed by uvular ejective	•
[ɴǃɢ], ǃɢ	Voiced uvular plosive (usually prenasalized)	•		•				•
[(ɴ)ǃɢh, (ɴ)ǃɢx, (ɴ)ǃɢʀ]	Voiced (or prenasalized) uvular plosive, followed by aspiration, velar fricative, or uvular trill	•

Click genesis and click loss

It is not known how clicks arose. It is often suggested that they developed from other complex consonants, but the development of clicks from other consonants has never been observed.

Clicks are often portrayed as a primitive or primordial feature of human language, but we have no reason to suspect that they are very old compared to other speech sounds. In fact, given their complexity, they may be relatively recent.

However, several still vibrant languages demonstrate click loss. For example, the East Kalahari languages have lost a large percentage of their clicks, presumably due to Bantu influence. Generally a click is replaced by a consonant that retains the manner of articulation of the accompaniment and the place of articulation of the forward release: Alveolar click releases (the [ǃ] family) tend to leave behind a velar stop or affricate, such as [k], [ɡ], [ŋ], [k͡x]; while palatal clicks ([ǂ] etc.) leave behind a palatal stop such as [c], [ɟ], [ɲ], [c’], or a post-alveolar affricate [tʃ], [dʒ]; and dental clicks ([ǀ] etc.) tend to leave an alveolar affricate [ts] behind.

References

Ladefoged, Peter (1968), A phonetic study of West African languages: An auditory-instrumental survey. Cambridge University Press, 2nd edition. ISBN 0-521-06963-7
Ladefoged, Peter and Ian Maddieson (1996), The Sounds of the World's Languages. Oxford: Blackwell Publishers Ltd. ISBN 0-631-19815-6
Anthony Traill & Rainer Vossen (1997), Sound change in the Khoisan languages: new data on click loss and click replacement. JALL 18, 21-56.

External links

The contrary opinion:

Hartmut Traunmüller (2003) "Clicks and the idea of a human protolanguage", Phonum 9: 1 - 4 (Umeå University, Dept. of Philosophy and Linguistics)