The near-close near-back vowel is a type of vowel sound, used in some spokenlanguages. The symbol in the International Phonetic Alphabet for the near-close near-back rounded vowel is ʊ. This derives from a small turned capital Ω; although officially called a small Latin letter upsilon, it bears little resemblance to the Greek upsilon and is informally called "horseshoeu" instead. The equivalent X-SAMPA symbol is U. Prior to 1989, there was an alternate IPA symbol for this sound, ɷ, called "closed omega". This symbol is no longer supported by the IPA.
Some languages may have a near-close near-back unrounded vowel; since no language is known to contrast rounding of this vowel, the IPA has not devised a standard way to represent this and thus can be represented in a number of ways, including <ɯ̽> and <ʊ̜>.
Its vowel backness is near-back, which means the tongue is positioned as in a back vowel, but slightly further forward in the mouth.
Its vowel roundedness is rounded, which means that the lips are rounded. However, no language is known to contrast rounding this place of articulation, so the IPA symbol has not devised separate symbols.
Occurrence
In the following transcriptions, the unrounded vowel is represented by the "less-rounded" diacritic [ʊ̜]:
The near-close central rounded vowel is a type of vowel sound, used in some spoken languages. The International Phonetic Alphabet can represent this sound as < ʊ̈ > (centralizedʊ) or < ʉ̞ > (loweredʉ). Recently the OED has adopted an unofficial extension of the IPA, ʊ̵, that is a conflation of ʊ and ʉ, for this sound or for free variation between [ʊ] and [ə].
