labiodentalis

Labiodentalis is a term used in phonetics and linguistics to describe a sound produced by bringing the lower lip into contact with the upper teeth. These sounds are classified as consonants. The most common labiodental sounds are the voiceless fricative [f] and the voiced fricative [v]. In these sounds, air is forced through the narrow gap between the lower lip and the upper teeth, creating friction.

The articulators involved are the lower lip (labio-) and the upper teeth (-dental). The lower lip provides the point of articulation, while the upper teeth form the surface against which the lip is pressed. The airflow is then modified to create either a voiceless sound, meaning the vocal cords do not vibrate, or a voiced sound, where the vocal cords do vibrate.

Labiodental fricatives are found in many languages worldwide, including English, where they appear in words such as "fan" /fæn/ and "van" /væn/. While less common, other labiodental sounds exist, such as the labiodental approximant, which is produced with less friction. The precise manner of articulation and voicing distinguishes the various labiodental consonants.