Voiceless linguolabial fricative

A voiceless linguolabial fricative is a type of consonantal sound used in some spoken languages. The symbol in the International Phonetic Alphabet that represents it is ⟨θ̼⟩ or less commonly ⟨s̼⟩ or ⟨f̼⟩.

• Its manner of articulation is fricative, which means it is produced by constricting air flow through a narrow channel at the place of articulation, causing turbulence.
• Its place of articulation is linguolabial, which means it is articulated with the tongue against the upper lip.
• Its phonation is voiceless, which means it is produced without vibrations of the vocal cords. In some languages the vocal cords are actively separated, so it is always voiceless; in others the cords are lax, so that it may take on the voicing of adjacent sounds.
• It is an oral consonant, which means that air is not allowed to escape through the nose.
• Its airstream mechanism is pulmonic, which means it is articulated by pushing air only with the intercostal muscles and abdominal muscles, as in most sounds.