The labiodental nasal is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , and the equivalent X-SAMPA symbol is F. The IPA symbol is a lowercase letter m with a leftward hook protruding the from the lower right of the letter. Occasionally it is instead transcribed as an with a dental diacritic: .

It is pronounced very similarly to the bilabial nasal , except instead of the lips touching each other, the lower lip touches the upper teeth. The position of the lips and teeth is generally the same as for the production of the other labiodental consonants, like and [v, though closure is obviously incomplete for the fricatives.

The labiodental nasal has not been confirmed to exist as a separate phoneme in any language. It has been reported from the Kukuya dialect of Teke, where it is "accompanied by strong protrusion of both lips". However, there is some doubt that a true stop can be made by this gesture (Ladefoged and Maddieson 1996: 18).

Nevertheless, it is extremely common phonetically, as it is the nearly universal allophone of (and sometimes ) before the labiodental fricatives and , as in English comfort or circumvent.

Features

Features of the labiodental nasal:

• Its manner of articulation is stop, which means it is produced by obstructing airflow in the vocal tract.
• Its place of articulation is labiodental which means it is articulated with the lower lips and the upper teeth.
• Its phonation type is voiced, which means the vocal cords are vibrating during the articulation.
• It is a nasal consonant, which means air is allowed to escape through the nose.
• 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.

It occurs in

• Greek: as an allophone of before the labiodental fricatives and , in words like αμφιθέατρο: , 'amphitheatre'.
• English: as an allophone of before the labiodental fricatives and , in words like symphony: .

Reference

Ladefoged, Peter, and Ian Maddieson (1996). Sounds of the World's Languages. Blackwells.

See also

• List of phonetics topics

Labial consonant

Stimmhafter labiodentaler Nasal | Consonne occlusive nasale labio-dentale voisée | 唇歯鼻音 | Spółgłoska nosowa wargowo-zębowa | Labiodental nasal