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, and the equivalent X-SAMPA symbol is B. The symbol is the Greek letter beta.
This letter is also often used to represent the bilabial approximant, though that is more clearly written with a lowering diacritic, that is. Theoretically, it could also be transcribed as an advanced labiodental approximant, but this symbol is hardly ever, if at all, used so. It has been proposed that either a turned ⟨⟩ or reversed ⟨⟩ be used as a dedicated symbol for the bilabial approximant, but despite occasional usage this has not 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.
The bilabial fricative is diachronically unstable and is likely to shift to.
The sound is not used in English dialects except for Chicano English, but it can be produced by approximating the normal English between the lips.

Features

Features of the voiced bilabial fricative:

Occurrence

Voiced bilabial fricative

Bilabial approximant