Voiced bilabial fricative

The voiced bilabial fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨β⟩, and the equivalent X-SAMPA symbol is B. The official symbol ⟨β⟩ is the Greek letter beta.

"β (IPA)" redirects here. For consonants followed by superscript ᵝ, see Labialization.

Voiced bilabial fricative
β
IPA number	127
Audio sample
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Encoding
Entity (decimal)	β
Unicode (hex)	U+03B2
X-SAMPA	B
Braille
Image

Voiced bilabial approximant
β̞
ʋ̟
Audio sample
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This letter is also often used to represent the bilabial approximant, though that is more precisely written with a lowering diacritic, that is ⟨β̞⟩. That sound may also be transcribed as an advanced labiodental approximant ⟨ʋ̟⟩, in which case the diacritic is again frequently omitted, since no contrast is likely.^[1][2] It has been proposed that either a turned ⟨β⟩, reversed ⟨β⟩ or affricate ⟨βθ⟩ can be used as a dedicated symbol for the bilabial approximant, but despite occasional usage none of them have gained general acceptance.^[3]

It is extremely rare for a language to make a phonemic contrast between the voiced bilabial fricative and the bilabial approximant. The Mapos Buang language of New Guinea contains this contrast. Its bilabial approximant is analyzed as filling a phonological gap in the labiovelar series of the consonant system rather than the bilabial series.^[4] Proto-Germanic^[5] and Proto-Italic^[6] are also reconstructed as having had this contrast, albeit with [β] being an allophone for another consonant in both cases. In Bashkir language, it is an intervocal allophone of /b/, and it is contrastive with /w/: балабыҙ [bɑɫɑˈβɯð] 'our child', балауыҙ [bɑɫɑˈwɯð] 'wax'.

The bilabial fricative is diachronically unstable (likely to be considerably varied between dialects of a language that makes use of it) and is likely to shift to [v].^[7]

The sound is not the primary realization of any sound in English dialects except for Chicano English, but it can be produced by approximating the normal English [v] between the lips; it can also sometimes occur as an allophone of /v/ after bilabial consonants.

Features

Features of the voiced bilabial fricative:

• Its manner of articulation is fricative, which means it is produced by constricting air flow through a narrow channel at the place of articulation, causing turbulence.
• Its place of articulation is bilabial, which means it is articulated with both lips.
• Its phonation is voiced, which means the vocal cords vibrate during the articulation.
• It is an oral consonant, which means air is allowed to escape through the mouth only.
• Because the sound is not produced with airflow over the tongue, the central–lateral dichotomy does not apply.
• Its airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the intercostal muscles and abdominal muscles, as in most sounds.

Occurrence

Voiced bilabial fricative

Language		Word	IPA	Meaning	Notes
Akei		[βati]		'four'
Alekano		hanuva	[hɑnɯβɑ]	'nothing'
Angor		fufung	[ɸuβuŋ]	'horn'
Bengali	Eastern dialects	ভিসা	[βisa]	'Visa'	Allophone of /v/ in Bangladesh and Tripura; /bʱ/ used in Western dialects.
Berta		[βɑ̀lɑ̀ːziʔ]		'no'
Catalan[8]		abans	[əˈβans]	'before'	Approximant or fricative. Allophone of /b/. Mainly found in betacist (/b/ and /v/ merging) dialects. See Catalan phonology
Chinese dialects	Fuzhou[9]	初八 chĕ̤ báik	[t͡sœ˥˧βaiʔ˨˦]	'eighth day of the month'	Allophone of /p/ and /pʰ/ in certain intervocalic positions.[9]
	Suburban Shanghainese	碗盞 ve tse	[βe̝˧˧˦tsɛ̝˥]	'bowl'	Usually [ɦu] or [u] in other Wu dialects[10]
Comorian		upvendza	[uβendza]	'to love'	Contrasts with both [v] and [w]
Coptic	Bohairic	ⲧⲱⲃⲓ	[ˈdoːβi]	'brick'	Shifted to [w] with a syllable coda allophone of [b] in a later stage.
	Sahidic	ⲧⲱⲱⲃⲉ	[ˈtoːβə]
Dahalo[11]		[koːβo]		'to want'	Weak fricative or approximant. It is a common intervocalic allophone of /b/, and may be simply a plosive [b] instead.[11]
English	Some dialects	upvote	[ˈʌpˌβoʊt]	'upvote'	Less-common allophone of /v/ after [p], [b], or [m] (the more-common alteration being the shifting of the earlier consonant to [p̪], [b̪], or [ɱ], respectively, although [p̪v]/[b̪v]/[ɱv] exist in free variation with [pβ]/[bβ]/[mβ]).
	Chicano	very	[βɛɹi]	'very'	May be realized as [b] instead.
Ewe[12]		Eʋe	[èβe]	'Ewe'	Contrasts with both [v] and [w]
Fijian		ivava	[iβa:βa:]	'shoe'
German[13][14]		aber	[ˈaːβɐ]	'but'	Intervocalic and pre-lateral allophone of /b/ in casual speech.[13][14] See Standard German phonology
Hopi		tsivot	[tsi:βot]	'five'
Japanese[15]		神戸/kōbe	[ko̞ːβe̞]	'Kobe'	Allophone of /b/ only in fast speech between vowels. See Japanese phonology
Kabyle		bri	[βri]	'to cut'
Kinyarwanda		abana	[aβa:na]	'children'
Korean		추후/chuhu/追後	[ˈt͡ɕʰuβʷu]	'later'	Intervocalic allophone of /h/ before /u/ and /w/. See Korean phonology
Luhya	Wanga Dialect	Nabongo	[naβonɡo]	'title for a king'
Mapos Buang[4]		venġévsën	[βəˈɴɛβt͡ʃen]	'prayer'	Mapos Buang has both a voiced bilabial fricative and a bilabial approximant as separate phonemes. The fricative is transcribed as ⟨v⟩, and the approximant as ⟨w⟩.[4]
Nepali		सभा	[sʌβä]	'Meeting'	Allophone of /bʱ/. See Nepali phonology
Portuguese	European[16][17]	sábado	[ˈsaβɐðu]	'Saturday'	Allophone of /b/. See Portuguese phonology
Ripuarian	Colognian[citation needed]	wing	[βɪŋ]	'wine'	Allophone of syllable-initial /v/ for some speakers; can be [ʋ ~ w ~ ɰ] instead.[citation needed] See Colognian phonology
Sardinian	Logudorese[18]	paba	[ˈpäːβä]ⓘ	'pope'	Intervocalic allophone of /b/ as well as word-initial /p/ when the preceding word ends with a vowel and there is no pause between the words.[18]
Turkish[19]		vücut	[βy̠ˈd͡ʒut̪]	'body'	Allophone of /v/ before and after rounded vowels.[19] See Turkish phonology
Turkmen		watan	[βatan]	'country'
Venda[20]		davha	/daβa/	'work party held by one who wants to have the land ploughed or cultivated'	Contrasts with /v/ and /w/
Zapotec	Tilquiapan[21]	[example needed]			Allophone of /b/

Bilabial approximant

Language		Word	IPA	Meaning	Notes
Amharic[22]		አበባ	[aβ̞əβ̞a]	'flower'	Allophone of /b/ medially between sonorants.[22]
Asturian		abanicu	[aβ̞aˈniku]	'swing'	Allophone of /b/
Basque[23]		alaba	[alaβ̞a]	'daughter'	Allophone of /b/
Catalan[8]		abans	[əˈβ̞ans]	'before'	Approximant or fricative. Allophone of /b/. Mainly found in betacist (/b/ and /v/ merging) dialects. See Catalan phonology
Cia-Cia		ᄫᅡᆯ루/walu	[β̞alu]	'eight'	Allophone of /β/
Dutch	Southern[24]	wang	[β̞aŋ]ⓘ	'cheek'	Labiovelar [ʋ] in northern Dutch.
Indonesian		tawa	[taβ̞a]	'laugh'	Allophone of /w/ by some younger speakers.
Japanese		私/watashi	[β̞ätäɕi]	'me'	Usually represented phonemically as /w/.[25] See Japanese phonology
Katë[26]	Western	dav	[d̪aβ̞]	'wood'	Corresponds to [ʋʷ] and [v] in other dialects.
Kyrgyz		ооба	[оːˈβ̞a]	'yes'	Allophone of /b/ medially between vowels.
Limburgish[27][28]		wèlle	[ˈβ̞ɛ̝lə]	'to want'	The example word is from the Maastrichtian dialect.
Lombard		el nava via	[el ˈnaβ̞a ˈβ̞ia]	'he was going away'	Regular pronunciation of /v/ when intervocalic. Used also as an allophone for other positions.
Mapos Buang[4]		wabeenġ	[β̞aˈᵐbɛːɴ]	'kind of yam'	Mapos Buang has both a voiced bilabial fricative and a bilabial approximant as separate phonemes. The fricative is transcribed as {v}, and the approximant as {w}.[4]
Occitan	Gascon	lavetz	[laˈβ̞ets]	'then'	Allophone of /b/
Ripuarian	Kerkrade[29]	sjwaam	[ʃβ̞aːm]	'smoke'	Weakly rounded; contrasts with /v/.[29] See Kerkrade dialect phonology
Spanish[30]		lava	[ˈläβ̞ä]	'lava'	Ranges from close fricative to approximant.[31] Allophone of /b/. See Spanish phonology
Swedish	Central Standard[32]	aber	[ˈɑːβ̞eɾ]	'problem'	Allophone of /b/ in casual speech. See Swedish phonology
Ukrainian[33]		вона	[β̞oˈnɑ]	'she'	An approximant; the most common prevocalic realization of /w/. Can vary with labiodental [ʋ].[33] See Ukrainian phonology

See also

• Index of phonetics articles