The voiced uvular fricative or approximant is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʁ⟩, an inverted small uppercase letter ⟨ʀ⟩, or in broad transcription ⟨ɣ⟩ or (if rhotic) ⟨r⟩. This consonant is one of several collectively called guttural R when found in European languages.
Because the IPA symbol stands for both the uvular fricative and the uvular approximant, the fricative nature of this sound may be specified by adding the uptack to the letter: ⟨ʁ̝⟩. The approximant can be specified by adding the downtack: ⟨ʁ̞⟩, though some writings use a superscript ⟨ʶ⟩, which is not an official IPA practice.
For a voiced pre-uvular fricative (also called post-velar), see voiced velar fricative.
Voiced uvular fricative Wikipedia
Features of the voiced uvular 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. In many languages it is closer to an approximant, however, and no language distinguishes the two at the uvular articulation.
Its place of articulation is uvular, which means it is articulated with the back of the tongue (the dorsum) at the uvula.
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.
It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.
In Western Europe, a uvular trill pronunciation of rhotic consonants spread from northern French to several dialects and registers of Basque, Catalan, Danish, Dutch, German, Hebrew, Judaeo-Spanish, Norwegian, Occitan, Portuguese, Swedish, and Yiddish. However, not all of these remain a uvular trill today. In Brazilian Portuguese, it is usually a velar fricative ([x], [ɣ]), voiceless uvular fricative [χ], or glottal transition ([h], [ɦ]), except in southern Brazil and Rio de Janeiro, where alveolar, velar and uvular trills and the voiced uvular fricative predominate. Because such uvular rhotics often do not contrast with alveolar ones, IPA transcriptions may often use ⟨r⟩ to represent them for ease of typesetting. For more information, see guttural R.
Ladefoged & Maddieson (1996) note that "There is (...) a complication in the case of uvular fricatives in that the shape of the vocal tract may be such that the uvula vibrates." See voiced uvular raised non-sonorant trill for more information.