Labialization

Labialization is a secondary articulatory feature of sounds in some languages. Consonants pronounced this way are said to be labialized and are usually transcribed in the International Phonetic Alphabet by affixing a superscript w, ⟨ʷ⟩, to the base letter. Labialized sounds involve the lips while the remainder of the oral cavity produces another sound. The term is normally restricted to consonants. When vowels involve the lips, they are called rounded.

In phonology, "labialization" may also refer to a type of assimilation process.

Labialized consonants

The most common labialized consonants are labialized velars. Most other labialized sounds also have simultaneous velarization, and the process may then be more precisely called labio-velarization. The labialization of bilabial consonants, though generally transcribed with ⟨◌ʷ⟩ as if it were labiovelar, is often a protrusion of the lips without velarization of the tongue.

Labialization has been attested with pulmonic, implosive, ejective and click consonants. All places and manners of pulmonic consonants are attested with labialized variants, with the possible exception of the epiglottals.

Occurrence

Labialization is the most widespread secondary articulation in the world's languages. It is phonemically contrastive in Northwest Caucasian (e.g. Adyghe), Athabaskan, and Salishan language families, among others. This contrast is reconstructed also for Proto-Indo-European, the common ancestor of the Indo-European languages, and it survives in Latin and some Romance languages. It is also found in the Cushitic and Ethio-Semitic languages.

American English labializes /r,ʃ,ʒ,tʃ,dʒ/ to various degrees.[citation needed]

A few languages, including Arrernte, have contrastive labialized forms for nearly all of their consonants.

In many Salishan languages, such as Klallam, velar consonants only occur in their labialized forms (except /k/, which occurs in some loanwords); however, uvular consonants occur abundantly labialized and unrounded.

Types

Out of 706 language inventories surveyed by Ruhlen (1976), labialization occurred most often with velar (42%) and uvular (15%) segments and least often with dental and alveolar segments. With non-dorsal consonants, labialization may include velarization as well. Labialization is not restricted to lip-rounding. The following articulations have either been described as labialization or been found as allophonic realizations of prototypical labialization:

• Labiodental frication, found in Abkhaz
• Labiodentalization, including a common idiosyncrasy of English /s/ and /z/, and especially of /r/
• Complete bilabial closure, [d͡b,t͡p,t͡pʼ], found in Abkhaz and Ubykh
• "Labialization" (/w/, /ɡʷ/, and /kʷ/) without noticeable rounding (protrusion) of the lips, found in the Iroquoian languages. It may be that they are compressed.[citation needed]
• Rounding without velarization, found in Shona and in the Bzyb dialect of Abkhaz.[citation needed]

Eastern Arrernte has labialization at all places and manners of articulation; this derives historically from adjacent rounded vowels, as is also the case of the Northwest Caucasian languages. Marshallese also has phonemic labialization as a secondary articulation at all places of articulation except for labial consonants and coronal obstruents.

In North America, languages from a number of families have consonants that are perceptually (auditorily) labialized (and vowels that are perceptually rounded) but which lack any participation of the lips, such as the now-extinct Tillamook.

Similarly to the distinction between the labiopalatal [ɥ] and labiovelar [w] semivowels, some languages exhibit labiopalatalization [ᶣ], contrasting with labiovelarization [ʷ].

Prelabialization

In Slovene, sounds can be prelabialized. Furthermore, the change is phonemic and all phonemes have prelabialized pairs (though not all of their allophones can have pairs). Compare stati 'stand' [ˈs̪t̪àːt̪í] and vstati 'stand up' [ˈʷs̪t̪àːt̪í]. The prelabialization part, however, is usually not considered as being part of the same phoneme as prelabialized sound, but rather as an allophone of /ʋ/ as it changes depending on the environment, e. g. vzeti 'take' [ˈʷz̪èːt̪í] and povzeti 'summarize' [pou̯ˈz̪èːt̪í]. See Slovene phonology for more details.

Transcription

In the International Phonetic Alphabet, protruded labialization is indicated with a raised ⟨w⟩ modifier [ʷ], as in /kʷ/. There are also diacritics, respectively [ɔ̹],[ɔ̜], to indicate greater or lesser degrees of rounding. These are normally used with vowels but may occur with consonants. For example, in Hupa, an Athabaskan language, voiceless velar fricatives distinguish three degrees of labialization, transcribed either /x/,/x̹/,/xʷ/ or /x/,/x̜ʷ/,/xʷ/.

The VoQS system has two additional symbols for degrees of rounding, originally introduced as part of the extensions to the IPA: Spread [i͍] and open-rounded [ʃꟹ] (as in English and French). It also has a symbol for labiodentalized sounds, [tᶹ], which the IPA Handbook (1999) states may also be used for protruded labialization if ⟨ʷ⟩ is additionally specifying simultaneous velarization.

If precision is desired, the Abkhaz and Ubykh articulations may be transcribed with the appropriate fricative or trill raised as a diacritic: [tᵛ], [tᵝ], [t𐞄], [tᵖ].

For simple labialization, Ladefoged & Maddieson (1996) resurrected an old IPA symbol, [̫], which would be placed above a letter with a descender such as ɡ. However, their chief example is Shona sv and zv, which they transcribe /s̫/ and /z̫/ but which actually seem to be whistled sibilants, without necessarily being labialized. Another possibility is to use the IPA diacritic for rounding, distinguishing for example the labialization in English soon [s̹] and [sʷ] swoon. The open rounding of English /ʃ/ is also unvelarized.

Assimilation

Labialization also refers to a specific type of assimilatory process where a given sound become labialized due to the influence of neighboring labial sounds. For example, /k/ may become /kʷ/ in the environment of /o/, or /a/ may become /o/ in the environment of /p/ or /kʷ/.

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 phonemic vowels. This appears to have been the case in Ubykh and Eastern Arrernte, for example. The labial vowel sounds usually still remain, but only as allophones next to the now-labial consonant sounds.

List of labialized consonants

Note that labialized palatal clicks are not attested in Yeyi and are not reconstructed for Proto-Kxʼa. Xhosa also has prenasalized tenuis/ejective and aspirated clicks, which also occur labialized (nkqw, nkxw, nchw, nqhw, nxhw).

See also

• Labio-palatalization (◌ᶣ)

Bibliography

• Crowley, Terry (1997). An Introduction to Historical Linguistics (3rded.). Oxford University Press.
• Ladefoged, Peter; Maddieson, Ian (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN0-631-19815-6.
• Ruhlen, Merritt (1976). A Guide to the Languages of the World. Stanford University Press.

• Yanushevskaya, Irena; Bunčić, Daniel (2015). . Journal of the International Phonetic Association. 45 (2): 221–228. doi:.