Bilabial trill

The 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 $\langle\rangle$, and the equivalent X-SAMPA symbol is B\.

In many of the languages where the bilabial trill occurs, it only occurs as part of a prenasalized bilabial stop with trilled release,. This developed historically from a prenasalized stop before a relatively high back vowel, such as. In such instances, these sounds are usually still limited to the environment of a following.

A few languages, such as Mangbetu of Congo and Ninde of Vanuatu, have both a voiced and a voiceless bilabial trill.

There is also a very rare voiceless alveolar bilabially trilled affricate, (occasionally written "tᵖ") reported from Pirahã and from a few words in the Chapacuran languages Wari’ and Oro Win. 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.