Voiceless bilabial fricative - Definition and Overview

IPA - Unicode	ɸ
IPA - image
X-SAMPA	p\
Kirshenbaum	P
Sound sample

The voiceless bilabial fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ɸ, and the equivalent X-SAMPA symbol is p\. Features of this consonant:

• 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 bilabial which means it is articulated with both lips.
• Its phonation type is voiceless, which means it is produced without vibrations of the vocal cords.
• It is an oral consonant, which means air is allowed to escape through the mouth.
• It is a central consonant, which means it is produced by allowing the airstream to flow over the middle of the tongue, rather than the sides.
• The airstream mechanism is pulmonic egressive, which means it is articulated by pushing air out of the lungs and through the vocal tract, rather than from the glottis or the mouth.

Occurs as:

• Greek phoneme /φ/
• Spanish phoneme /f/
• Japanese phoneme /f/

This consonant is lacking in English, and English speakers will often pronounce voiceless labiodental fricative when speaking a language that has it, while speakers of a language that has it may use it in place of English 'f'.