labialvelar

Labial-velar, also called labiovelar, designates a place of articulation for consonants produced by a simultaneous closure or near-closure of the lips (bilabial) and the velum. It yields a single doubly articulated segment that cannot always be cleanly separated into a bilabial and a velar component, depending on linguistic analysis.

The best-known labial-velar segments are the stops [k͡p] (voiceless) and [ɡ͡b] (voiced). In some languages, other labiovelars occur as well, including nasal and possibly affricate varieties such as [ŋ͡m], which are articulated with the same double gesture. In phonetic transcription, the tie bar indicates simultaneous articulation, for example k͡p and ɡ͡b. Some descriptions treat labiovelars as single places of articulation, while others analyze them as a labiovelar sequence involving a bilabial and a velar gesture.

Geographic and linguistic occurrence is notable in West and Central Africa, where labiovelars are part of the phoneme inventories of several languages. Among the best-known examples are languages that spell labial-velar stops with digraphs such as kp and gb in their orthographies, including Yoruba and Igbo. The labiovelar distinction is phonemic in these languages, setting them apart from plain velars or bilabials.

In typology and phonetics, labiovelars are often discussed in contrast to labialized velars (velars with lip rounding) and to sequences involving two independent articulations. They are considered relatively stable across generations in languages that maintain a double-articulation system.