Labial-velar approximant

The labial-velar approximant is a type of consonantal sound, used in certain spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is w, and the equivalent X-SAMPA symbol is w.

It corresponds to English w, Polish ł, Belarusian ў and the Old English letter ƿ. Additionally, /w/ is believed to occur in Australian Aboriginal languages.

Features

Features of the labial-velar approximant:

Its manner of articulation is approximant, which means it is produced by bringing one articulator close to another but without the vocal tract being narrowed to such an extent that a turbulent airstream is produced.
Its place of articulation is labial-velar which means it is articulated both with the lips and with the back part of the tongue (the dorsum) toward the soft palate (the velum). For many languages, such as English, it is actually a labialized velar consonant; that is, it is pronounced with the back of the tongue raised toward the velum, but in addition the lips are rounded. However, in some languages, such as Japanese, the lips are compressed, and the sound is closer to a true labial-velar. The Northern Iroquoian languages may be similar.
Its phonation type is voiced, which means the vocal cords are vibrating during the articulation.
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.