Labial-velar nasal

The labial–velar nasal is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ŋ͡m⟩.

The labial–velar nasal is found in West and Central Africa and eastern New Guinea.

Features

Features of the labial–velar nasal:

• Its manner of articulation is occlusive, which means it is produced by obstructing airflow in the vocal tract. Since the consonant is also oral, with no nasal outlet, the airflow is blocked entirely, and the consonant is a stop.
• Its place of articulation is labial–velar, which means it is simultaneously articulated with the lips and with the back part of the tongue (the dorsum) against the soft palate (the velum). The dorsal closure is made and released slightly before the labial closure, but they overlap for most of their duration.
• Its phonation is voiced, which means the vocal cords vibrate during the articulation.
• It is a nasal consonant, which means air is allowed to escape through the nose, either exclusively (nasal stops) or in addition to through the mouth.
• Because the sound is not produced with airflow over the tongue, the central–lateral dichotomy does not apply.
• The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.

Occurrence

Rounded variant

Some languages, especially in Vanuatu, combine this labial–velar nasal with a labial–velar approximant release, hence [ŋ͡mʷ].

In the Banks Islands languages which have it, the phoneme /ŋ͡mʷ/ is written ⟨m̄⟩ in local orthographies, using a macron on the corresponding bilabial. In other languages of Vanuatu further south (such as South Efate, or Lenakel), the same segment is spelled ⟨m̃⟩ with a combining tilde.

See also

• List of phonetics topics
• Doubly articulated consonant

References

Bibliography