The close-mid central unrounded vowel, or high-mid central unrounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɘ⟩. This is a reversed letter e, and should not be confused with the schwa⟨ə⟩, which is a turned e. It was added to the IPA in 1993; before that, this vowel was transcribed ⟨ë⟩ (Latin small letter e with umlaut, not Cyrillic small letter yo). This letter may be used with a lowering diacritic⟨ɘ̞⟩, to denote the mid central unrounded vowel.
The IPA prefers terms "close" and "open" for vowels, and the name of the article follows this. However, a large number of linguists, perhaps a majority, prefer the terms "high" and "low".
Somewhat fronted, more so in Belgium. The height also varies, it's been variously described as lowered close-mid and raised close-mid. It's typically transcribed as /ɪ/, the way it's pronounced in some dialects. See Dutch phonology
Iivonen, Antti; Harnud, Huhe (2005), "Acoustical comparison of the monophthong systems in Finnish, Mongolian and Udmurt", Journal of the International Phonetic Association35 (1): 59–71, doi:10.1017/S002510030500191X