The open-mid back rounded vowel, or low-mid back rounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is . The IPA symbol is a turned letter c and both the symbol and the sound are commonly called "open-o". The name open-o represents the sound, in that it is like the sound represented by , the close-mid back rounded vowel, except it is more open. It also represents the symbol, which can be remembered as an o which has been "opened" by removing part of the closed circular shape.
In English, the symbol (or ) is typically associated with the vowel in "thought", but in Received Pronunciation ("RP", standard British English), Australian English, New Zealand English and South African English that vowel is produced with considerably stronger lip rounding and higher tongue position than that of cardinal , i.e. as close-mid or somewhat lower. Open-mid or even open realizations are found in North American English (where this vowel is often indistinguishable from the open back unrounded vowel in "bra") and Scottish English as well as Hiberno-English, Northern England English and Welsh English, though in the last three accent groups closer, -like realizations are also found. In RP, the open-mid realization of has been obsolete since the 1930s. Pronouncing that vowel as such is subject to correction for non-native speakers aiming at RP.
In Received Pronunciation and Australian English, the open-mid back rounded vowel occurs as the main allophone of the vowel . The contrast between and is thus strongly maintained, with the former vowel being realized as close-mid and the latter as open-mid , similarly to the contrast between and found in German, Italian and Portuguese.
Features
thumb|left|220px|[[Spectrogram of ]]
Occurrence
{| class="wikitable" style="clear: both;"
! colspan="2" | Language !! Word !! IPA!! Meaning !! Notes
|-
|Albanian||Tosk||||||'cake'||
|-
| Armenian || Eastern || hoġm|| || 'storm' ||
|-
| colspan="2" | Assamese || / kor || [kɔɹ] || 'to do' || May also be transcribed as fully low [ɒ] or "over-rounded" [ɒ̹]
|-
| Bavarian || Amstetten dialect || wås || || 'what' || Contrasts close , near-close , close-mid and open-mid back rounded vowels in addition to the open central unrounded . Typically transcribed in IPA with .
|-
| colspan="2" | Bengali || |||| 'meaning' || See Bengali phonology
|-
| colspan="2" | Breton || roll || [ˈrɔlː] || 'list' ||
|-
| colspan="2" | Bulgarian || rod|| || 'kin' || See Bulgarian phonology
|-
| colspan="2" | Catalan || || || 'clog' || See Catalan phonology
|-
| rowspan="2" |Chinese || Cantonese || ngo<sup>5</sup>|| || 'I, me, my' || See Cantonese phonology
|-
|Hokkien || bó͘ || || 'wife' || See Hokkien phonology
|-
| Cipu || Tirisino dialect || || || 'cut down!' || Near-back.
|-
| Danish || Standard || || || 'map' || Most often transcribed in IPA with . See Danish phonology
|-
| rowspan="2" | Dutch || Standard Belgian || rowspan="2" | || rowspan="2" | || rowspan="2" | 'alas' || rowspan="2" | 'Very tense, with strong lip-rounding', strongly pharyngealized (although less so in standard Belgian) and somewhat fronted. See Dutch phonology
|-
| Standard Northern ||
|-
| New Zealand || May be somewhat fronted. Often transcribed in IPA with . See New Zealand English phonology
|-
| Received Pronunciation || Most Scottish dialects exhibit the cot–caught merger, the outcome of which is a vowel of quality.
|-
| Sheffield|| goat || || 'goat' ||Common realization of the vowel particularly for males.
|-
| Newfoundland || but || || 'but' || Less commonly unrounded . || || || 'silly' (f.) || The Parisian realization has been variously described as a back vowel centralized to before See French phonology
|-
| colspan="2" | Galician || || ||'man' ||See Galician phonology
|-
| colspan="2" | Georgian || stsori|||| 'correct'||
|-
| German || Standard || || || 'full' || See Standard German phonology
|-
| rowspan="2" | Hindustani || Hindi || मुहब्बत(mohobbat) || rowspan="2" | || rowspan="2" | 'love','affection' || rowspan="2" | See Hindustani phonology.
|-
| Urdu || محبت(mohobbat)
|-
| colspan="2" | Italian || || || 'word' || Near-back. || align="center" | pó
||| 'stone' ||
|-
| colspan="2" | Kera || colspan="2" align="center" | || 'hard earth' || Near-back. || || || 'moon' || Lower in the Maastrichtian dialect. The example word is from the Hasselt dialect.
|-
| colspan="2" | Lower Sorbian || || || 'a request' ||
|-
| rowspan="3" | Low German || Most dialects || || || 'stick' || May be more open in the Netherlands or more closed in Low Prussian dialects.
|-
| Various dialects || || || 'sleep' || May be as low as and as high as in other dialects.
|-
| Southern Eastphalian|| || || 'bread' || Corresponds to in other dialects.
|-
| colspan="2" | Luxembourgish || || || 'son' || Possible realization of .
|-
| || || 'long' || Uncommon post-nasal allophone of , which is commonly raised to .
|-
| Norwegian || Some dialects || || || 'so' || Present e.g. in Telemark; realized as mid in other dialects. || || || 'cat' || See Polish phonology
|-
| rowspan="2" | Portuguese || Most dialects|| || || 'gossip' || Stressed vowel might be lower. The presence and use of other unstressed ⟨o⟩ allophones, such as , varies according to dialect.
|-
| Some speakers || || || 'scolding' || Stressed vowel, allophone of nasal vowel . See Portuguese phonology
|-
| Russian || Some speakers || sukhoy|| || 'dry' || More commonly realized as mid . || || || 'swamp' || Near-back. || || || 'dog' || See Upper Sorbian phonology
|-
| colspan="2" |Welsh
| siop
|
|'shop'
|See Welsh phonology
|-
| colspan="2" | West Frisian || || || 'rat' || See West Frisian phonology
|-
| colspan="2" |Yiddish
|
|[jɔ]
|'yes'
|See Yiddish phonology.
|-
| colspan="2" | Yoruba || colspan="3" | || Nasalized; may be near-open instead.