# 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.
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. 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.
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. Proto-Germanic and Proto-Italic 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].
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 | Language | Word | IPA | Meaning | Notes |
| Akei | Akei | [βati] | [βati] | 'four' | |
| Alekano | Alekano | hanuva | [hɑnɯβɑ] | 'nothing' | |
| Angor | Angor | fufung | [ɸuβuŋ] | 'horn' | |
| Bengali | Eastern dialects | ভিসা | [βisa] | 'Visa' | Allophone of /v/ in Bangladesh and Tripura; /bʱ/ used in Western dialects. |
| Berta | Berta | [βɑ̀lɑ̀ːziʔ] | [βɑ̀lɑ̀ːziʔ] | 'no' | |
| Catalan | Catalan | abans | [əˈβans] | 'before' | Approximant or fricative. Allophone of /b/. Mainly found in betacist (/b/ and /v/ merging) dialects. See Catalan phonology |
| Chinese dialects | Fuzhou | 初八 chĕ̤ báik | [t͡sœ˥˧βaiʔ˨˦] | 'eighth day of the month' | Allophone of /p/ and /pʰ/ in certain intervocalic positions. |
| Chinese dialects | Suburban Shanghainese | 碗盞 ve tse | [βe̝˧˧˦tsɛ̝˥] | 'bowl' | Usually [ɦu] or [u] in other Wu dialects |
| Comorian | 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. |
| Coptic | Sahidic | ⲧⲱⲱⲃⲉ | [ˈtoːβə] | 'brick' | |
| Dahalo | Dahalo | [koːβo] | [koːβo] | 'to want' | Weak fricative or approximant. It is a common intervocalic allophone of /b/, and may be simply a plosive [b] instead. |
| 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]). |
| English | Chicano | very | [βɛɹi] | 'very' | May be realized as [b] instead. |
| Ewe | Ewe | Eʋe | [èβe] | 'Ewe' | Contrasts with both [v] and [w] |
| Fijian | Fijian | ivava | [iβa:βa:] | 'shoe' | |
| German | German | aber | [ˈaːβɐ] | 'but' | Intervocalic and pre-lateral allophone of /b/ in casual speech. See Standard German phonology |
| Hopi | Hopi | tsivot | [tsi:βot] | 'five' | |
| Japanese | Japanese | 神戸/kōbe | [ko̞ːβe̞] | 'Kobe' | Allophone of /b/ only in fast speech between vowels. See Japanese phonology |
| Kabyle | Kabyle | bri | [βri] | 'to cut' | |
| Kinyarwanda | Kinyarwanda | abana | [aβa:na] | 'children' | |
| Korean | 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 | Mapos Buang | 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⟩. |
| Nepali | Nepali | सभा | [sʌβä] | 'Meeting' | Allophone of /bʱ/. See Nepali phonology |
| Portuguese | European | sábado | [ˈsaβɐðu] | 'Saturday' | Allophone of /b/. See Portuguese phonology |
| Ripuarian | Colognian | wing | [βɪŋ] | 'wine' | Allophone of syllable-initial /v/ for some speakers; can be [ʋ ~ w ~ ɰ] instead. See Colognian phonology |
| Sardinian | Logudorese | paba | | '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. |
| Turkish | Turkish | vücut | [βy̠ˈd͡ʒut̪] | 'body' | Allophone of /v/ before and after rounded vowels. See Turkish phonology |
| Turkmen | Turkmen | watan | [βatan] | 'country' | |
| Venda | Venda | davha | /daβa/ | 'work party held by one who wants to have the land ploughed or cultivated' | Contrasts with /v/ and /w/ |
| Zapotec | Tilquiapan | | | | Allophone of /b/ |

### Bilabial approximant

| Language | Language | Word | IPA | Meaning | Notes |
| Amharic | Amharic | አበባ | [aβ̞əβ̞a] | 'flower' | Allophone of /b/ medially between sonorants. |
| Asturian | Asturian | abanicu | [aβ̞aˈniku] | 'swing' | Allophone of /b/ |
| Basque | Basque | alaba | [alaβ̞a] | 'daughter' | Allophone of /b/ |
| Catalan | Catalan | abans | [əˈβ̞ans] | 'before' | Approximant or fricative. Allophone of /b/. Mainly found in betacist (/b/ and /v/ merging) dialects. See Catalan phonology |
| Dutch | Southern | werk | [β̞ɛr(ə)k] | 'work' | Labiovelar [ʋ] in northern Dutch. |
| Japanese | Japanese | 私/watashi | [β̞ätäɕi] | 'me' | Usually represented phonemically as /w/. See Japanese phonology |
| Katë | Western | dav | [d̪aβ̞] | 'wood' | Corresponds to [ʋʷ] and [v] in other dialects. |
| Kyrgyz | Kyrgyz | ооба | [оːˈβ̞a] | 'yes' | Allophone of /b/ medially between vowels. |
| Limburgish | Limburgish | wèlle | [ˈβ̞ɛ̝lə] | 'to want' | The example word is from the Maastrichtian dialect. |
| Lombard | 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 | Mapos Buang | 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}. |
| Occitan | Gascon | lavetz | [laˈβ̞ets] | 'then' | Allophone of /b/ |
| Ripuarian | Kerkrade | sjwaam | [ʃβ̞aːm] | 'smoke' | Weakly rounded; contrasts with /v/. See Kerkrade dialect phonology |
| Spanish | Spanish | lava | [ˈläβ̞ä] | 'lava' | Ranges from close fricative to approximant. Allophone of /b/. See Spanish phonology |
| Swedish | Central Standard | aber | [ˈɑːβ̞eɾ] | 'problem' | Allophone of /b/ in casual speech. See Swedish phonology |
| Ukrainian | Ukrainian | вона | [β̞oˈnɑ] | 'she' | An approximant; the most common prevocalic realization of /w/. Can vary with labiodental [ʋ]. See Ukrainian phonology |