Labial–velar consonants

Labial–velar consonants are doubly articulated at the velum and the lips. They are sometimes called "labiovelar consonants", a term that can also refer to labialized velars, such as [kʷ] and the approximant [w].

Truly doubly articulated labial–velars occur as plosives and nasal stops in the majority of languages in West and Central Africa (for example in the name of Laurent Gbagbo, former president of Ivory Coast; they are found in many Niger–Congo languages as well as in the Ubangian, Chadic and Central Sudanic families), and are relatively common in the eastern end of New Guinea. They include [k͡p, ɡ͡b, ŋ͡m]. To pronounce these, try saying [k, ɡ, ŋ], but close your lips as you would for [p, b, m]. Then release your lips as you produce the [k, ɡ, ŋ]. Note that, while 90% of the occlusion overlaps, the onset of the velar occurs slightly before that of the labial, and the release of the labial occurs slightly after that of the velar, so that the preceding vowel sounds as if followed by a velar, while the following vowel sounds as if followed by a labial. Thus the order of the symbols in k͡p and ɡ͡b is not arbitrary, but is motivated by the phonetic details of these sounds.

The Yélî Dnye language of Rossel Island, Papua New Guinea, has both labial–velars and labial–alveolar consonants. Labial–velar plosives and nasals also occur in Vietnamese, albeit only at the ends of words.

IPA	Description	Example
IPA	Description	Language	Orthography	IPA	Meaning
k͡p	voiceless labial–velar plosive	Logba	ò-kpàyɔ̀	[ò-k͡pàjɔ̀]	'God'
ɡ͡b	voiced labial–velar plosive	Ewe	Ewegbe	[ɛβɛɡ͡be]	'the Ewe language'
ŋ͡m	labial–velar nasal	Vietnamese	cung	[kuŋ͡m]	'sector'

These sounds are clearly single consonants rather than consonant clusters. The Eggon language, for example, contrasts these possibilities, with /bɡ/ and /ɡb/ both distinct from /ɡ͡b/. Ignoring tone, we have:

Single consonant		Two-consonant sequence
pom	to pound	kba	to dig
abu	a dog	bɡa	to beat, to kill
aku	a room	ak͡pki	a stomach
ɡom	to break	ɡ͡bɡa	to grind
k͡pu	to die	kpu	to kneel
ɡ͡bu	to arrive	ɡba	to divide

Note that, although such symbols are readily understood, they are not sanctioned by the IPA, and have no Unicode values. They can, however, be specified as the way an OpenType font displays gb and kp digraphs.

Labial–velar plosives also occur as ejective [k͡pʼ] and implosive [ɠɓ] (the tie bar has been removed for legibility). There may be labial–velar approximants in languages like Japanese. Bilabial clicks are sometimes considered to be labial–velar consonants as well, though the validity of this classification is debated.

For transcribing these sounds ligatures can occasionally be seen instead of digraphs with a tie bar:

File:Labial velars.png