Voiced labio-velar approximant


The voiced labio-velar approximant is a type of consonantal sound, used in certain spoken languages, including English. It is the sound denoted by the letter in the English alphabet; likewise, the symbol in the International Phonetic Alphabet that represents this sound is, and the equivalent X-SAMPA symbol is w. In most languages it is a labialized velar approximant, and the semivocalic counterpart of the close back rounded vowel - i.e. the non-syllabic close back rounded vowel. In inventory charts of languages with other labialized velar consonants, will be placed in the same column as those consonants. When consonant charts have only labial and velar columns, may be placed in the velar column, labial column, or both. The placement may have more to do with phonological criteria than phonetic ones.
Some languages have the voiced labio-prevelar approximant, which is articulated slightly more front compared with the place of articulation of the prototypical voiced labio-prevelar approximant, though not as front as the prototypical labialized palatal approximant.

Features

Features of the voiced labialized velar approximant:
The type of approximant is glide or semivowel. The term glide emphasizes the characteristic of movement of from the vowel position to a following vowel position. The term semivowel emphasizes that, although the sound is vocalic in nature, it is not 'syllabic'.
Some languages, such as Japanese and perhaps the Northern Iroquoian languages, have a sound typically transcribed as where the lips are compressed, which is a true labial–velar consonant. Close transcriptions may avoid the symbol in such cases, or may use the under-rounding diacritic,.

Occurrence