Bilabial trill

consonantal sound

The bilabial trill is a consonant. It is used in some spoken languages.

Bilabial trill
IPA number121
Entity (decimal)ʙ
Unicode (hex)U+0299


The International Phonetic Alphabet represents this sound as ⟨ʙ⟩. The X-SAMPA symbol of it is B\.

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

There is also voiceless alveolar bilabially trilled affricate ([t̪͡ʙ̥], sometimes "tᵖ"), which is not often used. It is found in 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 plosive /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:

  • Its behavior is trill. It means that we produce this sound by directing air over the articulator so that it vibrates. In most instances, it is only found as the trilled release of a prenasalized stop.


These are some examples where the bilabial trill is used in various languages:

Language Word IPA Meaning Notes
Kele[1] [ᵐʙulim] 'face'
Kom [ʙ̥ɨmɨ] 'to believe'
Pirahã [[[Latin alphabet|kaoáíbogi]]] Error: {{Lang}}: text has italic markup (help) [kàò̯áí̯ʙòˈɡì] 'evil spirit' allophone of /b/ before /o/
Titan[1] [ᵐʙutukei] 'wooden plate'
Ubykh[1] [t͡ʙ̥aχəbza] 'Ubykh language' allophone of /tʷ/.See Ubykh phonology.
Unua[2] [ᵐʙue] 'pig'
Wari’ [t͡ʙ̥ot͡ʙ̥oweʔ] 'chicken'


  1. 1.0 1.1 1.2 Ladefoged, Peter (2005). Vowels and Consonants (Second ed.). Blackwell. p. 165.
  2. Dimock, Laura (2005). "The Bilabial Trill in Unua" (PDF). Wellington Working Papers in Linguistics. 17: 19. ISSN 1170-1978. Retrieved 21 Nov. 2011. Check date values in: |access-date= (help)CS1 maint: ref duplicates default (link)

Other websitesEdit