Implosive consonant

Implosive consonants are plosives (rarely affricates) with a glottalic ingressive airstream mechanism. That is, the airsteam is controlled by moving the glottis downward, rather than by expelling air from the lungs as in normal pulmonic consonants. Contrastive implosives are found in approximately 10%-15% of the world's languages.

In the International Phonetic Alphabet, implosives are indicated by writing a plosive consonant with a hook top.

During the occlusion of the stop, pulling the glottis downward rarifies 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 is the easiest implosive to pronounce, and also most common around the world. Velar, on the other hand, is quite rare (and uvular 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.

Fully voiced plosives are often slightly implosive, although this is not always described explicitly, as there is no contrast with modal-voiced plosives in such languages. This is found around the world, from Maidu to Thai to many Bantu languages, including Swahili and Zulu.

Sindhi has an unusually large number of implosives, with. Although Sindhi has a dental-retroflex distinction in its plosives, this is neutralized in the alveolar implosive. Indeed, retroflex implosives are exceedingly rare (one has been claimed for Ngad'a, spoken in Flores, Indonesia: Djawanai 1997).

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".

Voiceless implosives are found in languages as varied as the Owere dialect of Igbo in Nigeria, Krongo in Sudan, and some dialects of the Quiche language in Guatemala, but they are quite rare. The IPA has removed its earlier dedicated symbols for them, so now the bilabial voiceless implosive is transcribed as.

(Owere Igbo has a seven-way contrast among bilabial stops: .)

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 rare 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.

The attested implosive stops are:


 * voiced bilabial implosive
 * voiced dental implosive
 * voiced alveolar implosive
 * voiced palatal implosive
 * voiced velar implosive
 * voiced uvular implosive

Reported but not confirmed is:
 * voiced retroflex implosive