Labiodental nasal

The labiodental nasal is a type of consonantal sound. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɱ⟩. The IPA symbol is a lowercase letter m with a leftward hook protruding from the lower right of the letter. Occasionally it is instead transcribed as an em with a dental diacritic: ⟨m̪⟩.

Contents

• Features
• Occurrence
• References

It is pronounced very similarly to the bilabial nasal [m], 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 [f] and [v], though closure is obviously incomplete for the fricatives.

Although commonly appearing in languages, it is overwhelmingly present non-phonemically, largely restricted to appear before labiodental consonants like [f] and [v]. A phonemic /ɱ/ has been reported for the Kukuya language, which contrasts it with /m, mpf, mbv/ and is "accompanied by strong protrusion of both lips". It is [ɱʷ] before /a/ and [ɱ] before /i/ and /e/, perhaps because labialization is constrained by the spread front vowels; it does not occur before back (rounded) vowels. However, there is some doubt that a true stop can be made by this gesture because of gaps between the incisors, which for many speakers would allow air to flow during the occlusion; this is particularly pertinent considering that one of the words with this consonant, /ɱáá/, means a 'gap between filed incisors,' a practice of the local people. The /ɱ/ might be better characterized as a labiodental nasal approximant than as a nasal occlusive.

Nonetheless, it is common phonetically, as it is a typical allophone of /m/ and /n/ before the labiodental fricatives [f] and [v], as in English comfort, circumvent, infinitive, or invent. In Angami, it occurs as an allophone of /m/ before /ə/.

A proposal to retire the letter ⟨ɱ⟩ was made at the Kiel Convention, at the same time the extensions to the IPA were presented, with the labiodental nasal to be transcribed solely by ⟨m̪⟩, but the proposal was defeated in committee.