Implosive consonants are stops (rarely affricates) with a mixed glottalic ingressive and pulmonic egressive airstream mechanism. That is, the airstream is controlled by moving the glottis downward in addition to expelling air from the lungs. Therefore, unlike the purely glottalic ejective consonants, implosives can be modified by phonation, which is almost universally voice. Contrastive implosives are found in approximately 13% of the world's languages.
In the International Phonetic Alphabet, implosives are indicated by modifying a voiced stop letter with a hook top: [? ? ? ? ?].
During the occlusion of the stop, pulling the glottis downward rarefies the air in the vocal tract. The stop is then released. In languages where implosives are particularly salient, this may result in air rushing into the mouth, before flowing out again with the next vowel. (Thus the name "implosive".) However, in others there is no movement of air at all, contrasting with the burst of the pulmonary plosives. This is the case with many of the Kru languages, for example.
The vast majority of implosive consonants are voiced, meaning that the glottis is only partially closed. Because the airflow required for voicing reduces the vacuum being created in the mouth, implosives are easiest to make with a large oral cavity. Thus bilabial [ɓ] is the easiest implosive to pronounce, and also most common around the world. Velar [ɠ], on the other hand, is quite rare (and uvular [ʛ] even rarer). This is the opposite pattern to the ejective consonants, where it is the velar articulation that is most common, and the bilabial that is rare.
Types of implosives
The attested implosive stops are:
Implosive affricates and fricatives are extremely unusual. Imploded affricates occur in Kung-Ekoka and Hendo (a Bantu language). Several Central Sudanic languages, such as Mangbetu, have implosive labiodental fricatives, which are "strongly imploded, the lower lip briefly pulled back into the mouth".
Consonants variously called "voiceless implosives", "implosives with glottal closure", or "reverse ejectives" involve a slightly different airstream mechanism, purely glottalic ingressive. Here the glottis is closed, so no pulmonic airstream is possible. The IPA once dedicated symbols <ƥ ƭ ƈ ƙ ʠ> to these sounds, but these were withdrawn in 1993. They are now transcribed <ɓ̥ ɗ̥ ʄ̊ ɠ̊ ʛ̊> or occasionally <pʼ↓ tʼ↓ cʼ↓ kʼ↓>. Some authors use a superscript left pointer, p˂ t˂ c˂ k˂, but this is not an IPA symbol and has other uses.
These sounds are quite rare but are found in languages as varied as the Owere dialect of Igbo in Nigeria ([ƥ ƭ]), Krongo in Sudan, the Uzere dialect of Isoko, the closely related Lendu and Ngiti languages in the Democratic Republic of Congo, Seereer-Siin in Senegal ([ƥ ƭ ƈ]), and some dialects of the Poqomchi’ and Quiche languages in Guatemala ([ƥ ƭ]). Owere Igbo has a seven-way contrast among bilabial stops, [p pʰ ɓ̥ b b̤ ɓ m], and its alveolar stops are similar. It does not appear that the dorsal stops [ƙ ʠ] are attested in the literature as speech sounds. However, some English speakers use a voiceless velar implosive [ƙ] to imitate the "glug-glug" sound of wine being poured from a bottle, though others use a voiced implosive.
Occurrence in languages
Implosives are commonplace among the Sub-Saharan African languages, are widespread in Southeast Asia, and are found in a few languages of the Amazon Basin. They are rarely reported elsewhere, but do occur in scattered languages such as Maidu and the Mayan languages in North America, and Sindhi in the Indian subcontinent. They appear to be entirely absent from Europe and Australia, even from the exotic Damin, which uses every other possible airstream mechanism. However, fully voiced stops are often slightly implosive, although this is not always described explicitly when there is no contrast with modal-voiced plosives. This is found around the world, from Maidu to Thai to many Bantu languages, including Swahili.
Sindhi has an unusually large number of contrastive implosives, with [ɓ ᶑ ʄ ɠ]. Although Sindhi has a dental-retroflex distinction in its plosives, with [b d ɖ ɟ ɡ], this contrast is neutralized in the implosives. A contrastive retroflex implosive ([ᶑ] may however occur in Ngad'a, a language spoken in Flores, Indonesia.
Published - November 2008
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