Mid back rounded vowel

The mid back rounded vowel is a type of vowel sound, used in some spoken languages. While there is no dedicated symbol in the International Phonetic Alphabet that represents the exact mid back rounded vowel between close-mid [o] and open-mid [ɔ], it is normally written ⟨o⟩. If precision is desired, diacritics may be used, such as ⟨o̞⟩ or ⟨ɔ̝⟩, the former being more common.

Multiple para-IPA alternative symbols also exist for this vowel. The Swedish Dialect Alphabet uses the symbol ⟨ⱺ⟩ (an o with low ring), while Sinological notation uses the symbol ⟨o̧⟩ (an o with cedilla). The symbol ⟨ꭥ⟩ (a small capital omega) was proposed for Americanist notation, but was never implemented.

Just because a language has only one non-close non-open back vowel, it still may not be a true-mid vowel. Tukang Besi is a language in Sulawesi, Indonesia, with a close-mid [o]. Taba, another language in Indonesia, in the Maluku Islands, has an open-mid [ɔ]. In both languages, there is no contrast with another mid (true-mid or close-mid) vowel.

Kensiu, in Malaysia and Thailand, is highly unusual in that it contrasts true-mid vowels with close-mid and open-mid vowels without any difference in other parameters, such as backness or roundedness.

Some of the vowels listed in the table below may phonetically be more front than typical back vowels, as near-back vowels. If precision is required, this may instead be called a mid near-back rounded vowel.