Bilabial clicks

The bilabial clicks are a family of click consonants that sound something like a smack of the lips. They are found as phonemes only in the small Tuu language family, in the ǂHõã language of Botswana (though reconstructed for the Kx'a family), and in the extinct Damin ritual jargon of Australia.

The symbol in the International Phonetic Alphabet that represents the place of articulation of these sounds is ⟨ʘ⟩. Either letter may be combined with a second letter to indicate the manner of articulation, though this is commonly omitted for tenuis clicks, and increasingly a diacritic is used instead. Common bilabial clicks are:

The last is what is heard in the sound sample at right, as non-native speakers tend to glottalize clicks to avoid nasalizing them.

Damin also had an egressive bilabial [ʘ↑], the world's only attested egressive click.

Features

Features of ingressive bilabial clicks:

• The basic articulation may be voiced, nasal, aspirated, glottalized, etc.
• The forward place of articulation is bilabial, which means it is articulated with both lips.^[1] The release is a noisy, affricate-like sound.
• Clicks may be oral or nasal, which means that the airflow is either restricted to the mouth, or passes through the nose as well.
• Because the sound is not produced with airflow over the tongue, the central–lateral dichotomy does not apply.
• The airstream mechanism is lingual ingressive (aka velaric ingressive), which means a pocket of air trapped between two closures is rarefied by a "sucking" action of the tongue, rather than being moved by the glottis or the lungs/diaphragm. The release of the forward closure produces the 'click' sound. Voiced and nasal clicks have a simultaneous pulmonic egressive airstream. (One of the two labial clicks in Damin is lingual egressive, which means that the trapped air pocket is compressed by the tongue until it is allowed to spurt out through the lips.)

The bilabial clicks are sometimes erroneously described as sounding like a kiss. However, they do not have the pursed lips of a kiss (that is, they're not rounded). Instead, they have an articulation more like that of a [p], and sound more like a smack of the lips.

Symbol

The bullseye or bull's eye (ʘ) symbol used in phonetic transcription of the phoneme was made an official part of the International Phonetic Alphabet in 1979, but had existed for at least 50 years earlier. It is encoded in Unicode as U+0298 LATIN LETTER BILABIAL CLICK.

Similar graphemes consisting of a circled dot encoded by Unicode are:

• Gothic 𐍈 ƕair
• astronomical symbol ☉ "Sun"
• mathematical operators ⊙ "circled dot operator" and ⨀ and "n-ary circled dot operator"
• geometrical symbol ◉ "fisheye"

A symbol created for the IPA,  (a turned b with a tail) was never widely used and was eventually dropped for ʘ.

Occurrence

English does not have a bilabial click (or any click consonant, for that matter) as a phoneme, but a plain bilabial click does occur in mimesis, as a lip-smacking sound children use to imitate a fish.

Labial clicks only occur in the Tuu and Kx'a families of southern Africa, and in the Australian ritual language Damin.

Notes

References

• Pullum, Geoffrey K.; Ladusaw, William A. (1996). Phonetic Symbol Guide. University of Chicago Press. pp. 132–133. 
• Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Blackwell Publishers. pp. 246–280. 

See also

• Alveolar clicks
• Dental clicks
• Lateral clicks
• Palatal clicks
• Retroflex clicks
• List of phonetics topics