Labial–coronal consonant

A labial–coronal consonant is a consonant produced with two simultaneous articulators: With the lips ('labial'; a p, b, or m sound), and with the tongue (at the gums, an 'alveolar' t, d, or n sound, or further back, a 'post-alveolar' ch, j, or ny sound).

Several languages have been claimed to have such sounds, such as Margi and Bura in Nigeria. However, most researchers interpret them as having sequences of labial and coronal consonants, a rather common occurrence in Africa. The Yélî Dnye language of Rossel Island, Papua New Guinea, appears to be unique in having distinct labial–alveolar and labial–postalveolar places of articulation, as illustrated below. (The alveolars are fronted, and the post-alveolars only slightly retracted, so it may be best not to consider the latter to be retroflex as they are sometimes described.)

Stops in Yelî Dnye	Bilabial		Alveolar		Postalveolar		Velar
Stop	paa	side	taa	knife	t̠oo	tongue	kaa	spear
Prenasalized stop	mbee	carry	nde	food	n̠d̠e	firewood	ŋɡaa	tree
Nasal	maa	road	nii	juice	n̠aa	feast	ŋa	lease

Stops in Yelî Dnye	Labial-alveolar		Labial–postalveolar		Labial–velar
Stop	t͡pənə	lung	t̠͡pənə	horn	k͡pene	coconut bag
Prenasalized stop	n͡md͡boo	pulp	n̠͡md̠͡boo	many	ŋ͡mɡ͡bo	fog
Nasal	n͡mo	bird	n̠͡mo	we	ŋ͡mo	breast

Labial–coronal allophones

In some Ghanaian languages such as Dagbani, and Nzema, there are palatalized allophones of labial–velars. These are sometimes mistakenly referred to as labial–alveolars, though they actually have a post-alveolar or palatal articulation instead of a true alveolar one.

Something similar is found with the labialized alveolar stops in several Northwest and Northeast Caucasian languages such as Abkhaz and Lak. Although the double stop articulation may be more common, they are generally considered to be essentially labialized alveolars because the labial contact is light, and moreover the contact is between the inner surfaces of the lips, which are protruded as they are for [w]. This is quite different from the normal contact for [p] in these languages. The labial contact may also be realized as a trill. Compare the following minimal sets in Ubykh:

da	now	dʷa ~ d͡ba ~ d͡ʙa	awl	ba	if
ta	pregnant	tʷa ~ t͡pa ~ t͡ʙa	cherry	pa	to weave
tʼə	ram	tʷʼə ~ t͡pʼə ~ t͡ʙʼə	to take out

Except for clicks, nearly all other doubly articulated consonants in the world are labial–velars. The labial-alveolars reported from some Chadic languages have upon investigation turned out to be /tp/, /db/, /nm/ and /dɓ/ sequences, not single consonants. (See Margi language.)

References

• Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN 0-631-19814-8.