Labialisation
Labialisation is a
secondary articulatory feature of sounds in some languages. Labialized sounds involve the lips while the remainder of the
oral cavity produces another sound. The term is normally used to refer to
consonants. When vowels involve the lips, they are usually called
rounded.
Labialzation may also refer to a type of
assimilation process.
Labialisation is the most widespread secondary articulation in the world's languages. It is phonemically contrastive in the
Northwest Caucasian,
Athabaskan,
Salishan, and
Indo-European language families, among others.
American English has three degrees of (phonetic) labialization: Fully rounded and initial , open-rounded , and unrounded, which in vowels is sometimes called spread. These secondary articulations are not universal. For example, while French shares the English open-rounding of , Russian does not. Such distinctions are helpful for non-native English speakers whose native languages use different articulations for sounds such as "r" and "l".
The most common form of labialisation is rounding of
dorsal consonants such as k, g, and q. With non-dorsal consonants, labialisation prototypically involves
velarization as well, so it might more accurately be called
labiovelarisation. However, this is not always the case, and labialisation is not restricted to lip-rounding. The following articulations have either been described as labialisation, or been found as
allophonic realisations of prototypical labialisation:
* Labial rounding, with or without protrusion of the lips (found in
Navajo)
* Labiodental frication, found in
Abkhaz* Bilabial frication, found in
Ubykh*
Bilabial trill, found in Ubykh
* Bilabial plosion, found in Ubykh
* "Labilialisation" without lip rounding, found in the
Iroquois* Rounding without velarization, found in
Shona and in the
Bzyb dialect of
AbkhazEastern
Arrernte is a language with labialisation at all
places and
manners of articulation. The labialisation derives historically from adjacent rounded vowels, as is also the case of the
Northwest Caucasian languages.
In the
International Phonetic Alphabet, labio-velarization of consonants is indicated with a raised
w modifier (
Unicode U+02B7), as in . There are also diacritics, respectively , to indicate greater or lesser degrees of rounding. These are normally used with vowels, but may occur with consonants. For example, in the
Athabaskan language Hupa,
voiceless velar fricatives distinguish three degrees of labialization, transcribed either or .
The
Extended IPA has two additional symbols for degrees of rouding: Spread and open-rounded . It also has a symbol for
labialdentalized sounds, .
If precision is desired, the Abkhaz and Ubykh articulations may be transcribed with the appropriate fricative or trill raised as a diacritic: , , , .
For simple labialization, Ladefoged and Maddieson resurrected an old IPA symbol, . In Shona, and contrast with and , and in some dialects with as well. The open rounding of English is also simple (unvelarized).
Labialisation also refers to a specific type of assimilatory process where a given sound become labialised due to the influence of neighboring labial sounds. For example, may become in the environment of , or may become in the environment of or .
In the
Northwest Caucasian languages as well as some
Australian languages rounding has shifted from the vowels to the consonants, producing a wide range of labialized consonants and leaving in some cases only two vowels. This appears to have been the case in Ubykh and
Eastern Arrernte, for example.
* Peter Ladefoged & Ian Maddieson,
The Sounds of the World's Languages (1996) ISBN 0631198156
