The voiceless labial–velar implosive is a rare type of consonantal sound. The sound exists in Igbo, though Clark says that it only occurs in the Central dialect of Igbo.[1][2]
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 plosive.
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 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 only.
It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
The airstream mechanism is implosive (glottalic ingressive), which means it is produced by pulling air in by pumping the glottis downward. As it is voiceless, the glottis is completely closed, and there is no pulmonic airstream at all.
^ abBickford, Anita C.; Floyd, Rick (2006). Articulatory phonetics : tools for analyzing the world's languages (4th ed.). Dallas: SIL International. ISBN9781556711657.
