are consonants articulated with both lips (bilabial
articulation) or with the lower lip and the upper teeth (labiodental
articulation). English [m] is a bilabial nasal
; [p] and [b] are bilabial stops
; [f] and [v] are labiodental fricatives
. Bilabial fricatives are less common but do occur in many languages; for example, the Spanish consonant spelt b
is pronounced as a voiced bilabial fricative [B] between vowels.
Lip rounding, or labialisation can also accompany other articulations, see labiovelars.