Voiced alveolar and postalveolar approximants

The voiced alveolar approximant is a type of consonantal sound used in some spoken languages. The symbol in the International Phonetic Alphabet that represents the alveolar and postalveolar approximants is ⟨ɹ⟩, a lowercase letter r rotated 180 degrees. The equivalent X-SAMPA symbol is r\.

The most common sound represented by the letter r in English is the voiced postalveolar approximant, pronounced a little more back and transcribed more precisely in IPA as ⟨ɹ̠⟩, but ⟨ɹ⟩ is often used for convenience in its place. For further ease of typesetting, English phonemic transcriptions might use the symbol ⟨r⟩ even though this symbol represents the alveolar trill in phonetic transcription.

The bunched or molar r sounds remarkably similar to the postalveolar approximant and can be described as a voiced labial pre-velar approximant with tongue-tip retraction. It can be transcribed in IPA as ⟨ψ[1] or ⟨ɹ̈⟩.

A schematic mid-sagittal section of an articulation of a voiced alveolar approximant [ɹ].
A schematic mid-sagittal section of an articulation of a voiced postalveolar approximant [ɹ̠].

As an allophone of other rhotic sounds, [ɹ] occurs in Edo, Fula, Murrinh-patha, and Palauan.[23]