|Near-close back rounded vowel|
The near-close back rounded vowel, or near-high back rounded vowel, is a type of vowel sound, used in some vocal languages. The IPA symbol that represents this sound is ⟨?⟩. It is informally called "horseshoe u". Prior to 1989, there was an alternate IPA symbol for this sound, ⟨?⟩, called "closed omega"; use of this symbol is no longer sanctioned by the IPA. In Americanist phonetic notation, the symbol ⟨?⟩ (a small capital U) is used. Sometimes, especially in broad transcription, this vowel is transcribed with a simpler symbol ⟨u⟩, which technically represents the close back rounded vowel.
Handbook of the International Phonetic Association defines [?] as a mid-centralized (lowered and centralized) close back rounded vowel (transcribed [u?] or [ü?]), and the current official IPA name of the vowel transcribed with the symbol ⟨?⟩ is near-close near-back rounded vowel. However, some languages have the close-mid near-back rounded vowel, a vowel that is somewhat lower than the canonical value of [?], though it still fits the definition of a mid-centralized . It occurs in some dialects of English (such as General American and Geordie) as well as some other languages (such as Maastrichtian Limburgish). It can be transcribed with the symbol ⟨⟩ (a lowered ⟨?⟩) in narrow transcription. For the close-mid (near-)back rounded vowel that is not usually transcribed with the symbol ⟨?⟩ (or ⟨u⟩), see close-mid back rounded vowel.
In some other languages (such as Bengali and Luxembourgish) as well as some dialects of English (such as Scottish) there is a fully back near-close rounded vowel (a sound between cardinal and ), which can be transcribed in IPA with ⟨⟩, ⟨u?⟩ or ⟨o?⟩.
A few languages also have the near-close back unrounded vowel (which does not have a separate IPA symbol) in their inventory.
The near-close back protruded vowel is typically transcribed in IPA simply as ⟨?⟩, and that is the convention used in this article. As there is no dedicated diacritic for protrusion in the IPA, symbol for the near-close back rounded vowel with an old diacritic for labialization, ⟨ ?⟩, can be used as an ad hoc symbol ⟨⟩ for the near-close back protruded vowel. Another possible transcription is ⟨⟩ or ⟨⟩ (a near-close back vowel modified by endolabialization), but this could be misread as a diphthong.
The close-mid near-back protruded vowel can be transcribed ⟨⟩ or ⟨⟩, whereas the fully back near-close protruded vowel can be transcribed ⟨u⟩, ⟨⟩ or ⟨u⟩.
Because back rounded vowels are assumed to have protrusion, and few descriptions cover the distinction, some of the following may actually have compression.
|Afrikaans||Standard||Botha||['bta]||'Botha'||Close-mid. Allophone of // in less stressed words, in stressed syllables of polysyllabic words and word-finally when unstressed. In the second case, it is in free variation with the diphthongal realization [ ~ ~ ]. See Afrikaans phonology|
|Assamese||?||[pt]||'to bury'||Close-mid; also described as open .|
|Bengali||?||['t?umi:]||'you'||Fully back; typically transcribed in IPA with ⟨u⟩. See Bengali phonology|
|[m]||'smooth'||Allophone of /u/ in syllables closed by a glottal stop and when nasalized.|
|Chinese||Mandarin||? / hóng||'red'||Fully back; height varies between mid and close depending on the speaker. See Standard Chinese phonology|
|Shanghainese||?||[k?¹]||'melon'||The height varies between close and close-mid; contrasts with a close to close-mid back compressed vowel.|
|Danish||Standard||mave||['m?:?]||'stomach'||Phonetic realization of the sequence /v?/. See Danish phonology|
|Dutch||Standard Northern||oren||['?:r?(n)]||'ears'||Allophone of /o:/ before /r/. Can be a centering diphthong  instead, especially before coda /r/. See Dutch phonology|
|Some speakers||hok||[k]||'den'||Contrasts with in certain words, but many speakers have only one vowel . See Dutch phonology|
|English||Australian||hook||[h?k]||'hook'||Also described as close back . See Australian English phonology|
|Welsh||In Cardiff, it is advanced and lowered to , often also with unrounding to .|
|Cockney||[k]||Sometimes fronted to .|
|Conservative Received Pronunciation||[hk]||Often lowered and advanced to , or unrounded to . See English phonology|
|Multicultural London||May be front instead.|
|New Zealand||The height varies between near-close and close-mid; it is unrounded and advanced to [ ~ ?] in some lexical items. See New Zealand English phonology|
|Some Estuary speakers||Often advanced to [ ~ ?], or advanced and lowered to [? ~ ].|
|French||Quebec||foule||[f?l]||'crowd'||Allophone of /u/ in closed syllables. See Quebec French phonology|
|German||Standard||Stunde||'hour'||The quality has been variously described as near-close back  and close-mid near-back . For some speakers, it may be as high as . See Standard German phonology|
|Hindustani||/?||[g?'lä:b]||'rose'||See Hindustani phonology|
|Hungarian||ujj||[?j:]||'finger'||Typically transcribed in IPA with ⟨u⟩. See Hungarian phonology|
|Irish||Munster||dubh||[dv?]||'black'||Allophone of /?/ between broad consonants. See Irish phonology|
|Italian||Central-Southern accents||ombra||['o?mbrä]||'shade'||Fully back; local realization of /o/. See Italian phonology|
|Kurdish||Kurmanji (Northern)||gul||[g?l]||'flower'||See Kurdish phonology|
|Limburgish||Some dialects||póp||[pp]||'doll'||Close-mid in the Maastrichtian dialect. The example word is from that dialect.|
|Luxembourgish||Sprooch||[?p?o?:?]||'language'||Fully back. Typically transcribed in IPA with ⟨o:⟩. See Luxembourgish phonology|
|Pashayi||Lower Darai Nur dialect||[sr]||'sun'||Close-mid.|
|Portuguese||Brazilian||pulo||['pul?]||'leap'||Reduction and neutralization of unstressed /u, o, ?/; can be voiceless. See Portuguese phonology|
|Russian||??||'dry'||Unstressed allophone of /u/. See Russian phonology|
|Saterland Frisian||Roop||[?o?:p]||'rope'||Phonetic realization of /o:/ and /?/. Near-close back [o?:] in the former case, close-mid near-back  in the latter. Phonetically, the latter is nearly identical to /?:/ .|
|Scots||Glenoe dialect||go||[?o?:]||'go'||Fully back.|
|Sinhalese||[example needed]||[ak]||'much'||Only weakly rounded; typically transcribed in IPA with ⟨u⟩.|
|Slovak||ruka||['ru?kä]||'arm'||Typically fully back. See Slovak phonology|
|Sotho||potso||[p't?s'?]||'query'||Fully back; contrasts close, near-close and close-mid back rounded vowels. See Sotho phonology|
|Spanish||Eastern Andalusian||tus||[t:]||'your' (pl.)||Fully back. Corresponds to in other dialects, but in these dialects they are distinct. See Spanish phonology|
|Turkish||buzlu||[buz?'l]||'icy'||Allophone of /u/ described variously as "word-final" and "occurring in final open syllable of a phrase". See Turkish phonology|
|Ukrainian||??||[m?'sij]||'Musiy' (name)||See Ukrainian phonology|
|Yoruba||[example needed]||Near-back or back; typically transcribed in IPA with ⟨?⟩. It is nasalized, and may be close [ ~ ?] instead.|
|Near-close back compressed vowel|
Some languages, such as Norwegian, are found with a near-close back vowel that has a distinct type of rounding, called compressed or exolabial.
There is no dedicated diacritic for compression in the IPA. However, the compression of the lips can be shown with the letter ⟨⟩ as ⟨⟩ (simultaneous  and labial compression) or ⟨⟩ ( modified with labial compression). The spread-lip diacritic ⟨ ? ⟩ may also be used with a rounded vowel letter ⟨⟩ as an ad hoc symbol, though technically 'spread' means unrounded.
Only the Shanghainese dialect is known to contrast this with the more typical protruded (endolabial) near-close back vowel, although the height of both of these vowels varies from close to close-mid.
The fully back variant of the near-close compressed vowel can be transcribed ⟨⟩, ⟨⟩ or ⟨u⟩.
|Chinese||Shanghainese||?||[t¹]||'capital'||The height varies between close and close-mid; contrasts with a close to close-mid back protruded vowel.|
|Norwegian||ond||[n:]||'evil'||The example word is from Urban East Norwegian, in which the vowel has been variously described as near-close back  and close back . See Norwegian phonology|
|Swedish||Central Standard||ort||'locality'||The quality has been variously described as near-close near-back , near-close back  and close back . See Swedish phonology|