Voiced labiodental flap

In phonetics, the voiced labiodental flap is a speech sound found primarily in languages of Central Africa, such as Kera and Mangbetu. It has also been reported in the Austronesian language Sika. It is one of the few non-rhotic flaps. The sound begins with the lower lip placed behind the upper teeth. The lower lip is then flipped outward, striking the upper teeth in passing.