Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The voiceless labiodental fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is f, and the equivalent X-SAMPA symbol is f.Features of the voiceless labiodental fricative: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 labiodental which means it is articulated with the lower lips and the upper teeth.