A voiceless bilabial trill is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is . Some sources use a para-IPA symbol to transcribe this sound.
This sound is typologically extremely rare. It occurs in languages such as Pará Arára. Only a few languages contrast voiced and voiceless bilabial trills phonemically â e.g. Mangbetu and Dongo of DR Congo and Ninde of Vanuatu.
Features of a bilabial trill:
There is also a very rare voiceless bilabially post-trilled dental or alveolar stop, (written in Everett & Kern) reported from a few words in the Chapacuran languages Wariü, Itene (More), and Oro Win, as well as Sangtam, a Naga language. The sound also appears as an allophone of the labialized voiceless alveolar stop of Abkhaz and Ubykh, but in those languages it is more often realised by a doubly articulated stop . In the Chapacuran languages, is reported almost exclusively before rounded vowels such as and .
Additionally, the Efe dialect of Lese has a doubly articulated labialâÂÂvelar with trilled release , which occurs as an allophone of the voiceless labialâÂÂvelar plosive .
In some languages, the trill may be voiced, particularly when syllabic; see .