|Voiceless bilabial trill|
The 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 ⟨ʙ̥⟩. The X-SAMPA symbol is
This sound is typologically extremely rare. It occurs in languages such as Pará Arára and Sercquiais.
Only a few languages contrast voiced and voiceless bilabial trills phonemically – e.g. Mangbetu of Congo and Ninde of Vanuatu.
There is also a very rare voiceless alveolar bilabially trilled affricate, [t̪͡ʙ̥] (written ⟨tᵖ̃⟩ in Everett & Kern) reported from Pirahã and from a few words in the Chapacuran languages Wariʼ and Oro Win. The sound also appears as an allophone of the labialized voiceless alveolar stop /tʷ/ of Abkhaz and Ubykh, but in those languages it is more often realised by a doubly articulated stop [t͡p]. In the Chapacuran languages, [tʙ̥] is reported almost exclusively before rounded vowels such as [o] and [y].
Features of the bilabial trill:
|Pará Arára||[ʙ̥uta]||'to throw away'|
|Ubykh||тваҳəбза/tuaqhəbza||[t͡ʙ̥aχəbza]||'Ubykh language'||Allophone of /tʷ/. See Ubykh phonology|