The retroflex approximant is a type of consonantal sound, used in some spokenlanguages. The symbol in the International Phonetic Alphabet that represents this sound is 〈ɻ〉, and the equivalent X-SAMPA symbol is r\`. The IPA symbol is a turned lowercase letter r with a rightward hook protruding from the lower right of the letter.
Its phonation is voiced, which means the vocal cords vibrate during the articulation. However, in some languages (like Swiss German) it can just mean that this consonant is pronounced shorter and weaker than its voiceless counterpart, while its voicedness or lack thereof is not relevant. In such cases it's more accurate to call such sounds lenis or lax.
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.
This consonant, widely used in Old Kannada, has fallen out of use in writing and speaking in Modern Kannada; however, the Kannada script maintains a character for this consonant and it is present as a phoneme in certain dialects. See Old Kannada
^(Portuguese) Callou, Dinah. Leite, Yonne. "Iniciação à Fonética e à Fonologia". Jorge Zahar Editora 2001, p. 24
^Allophone of rhotic consonant, and seldom /l/, in the syllable coda. The retroflex approximant is stigmatized, being referred to as erre caipira (hillbilly ar, in free translation), mostly found in non-metropolitan hinterlands of São Paulo, Paraná, south of Minas Gerais and surrounding areas, but may also be post-alveolar, alveolar and/or rhotic vowel, the more common realization in metropolitan areas and the coast. As with [ɽ], it appeared as mutation of Iberian /ɾ/ in the development of Brazilian Portuguese from several Amerindian languages (most importantly the línguas gerais) and Old Portuguese (português arcaico) spoken by non-natives of the latter, in the countryside of its more southern states, while more northern dialects started to use the guttural sounds equivalent to Portuguese /ʁ/ in the syllable coda. Originally, both of these major variants elided ars in final of words with more than one syllable, a feature that as with many common Romance characteristics, colloquial Brazilian Portuguese still shares with languages such as Catalan, but now this trait is not more ubiquitous, neither with dialects that use guttural nor with those that use coronal approximant /r/. See Portuguese phonology