Close-mid central unrounded vowel Close-mid central unrounded vowel 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 . This is a mirrored letter e, and should not be confused with the schwa , which is a turned e. It was added to the IPA in 1993; before that, this vowel was transcribed (Latin small letter e with umlaut, not Cyrillic small letter yo). Certain older sources transcribe this vowel . The letter may be used with a lowering diacritic ,
Vowel harmony Vowel harmony Vowel harmony is a type of long-distance assimilatory phonological process involving vowels that occurs in some languages. A vowel or vowels in a word must be members of the same subclass (thus "in harmony"). In languages with vowel harmony, there are constraints on which vowels may be found near each other. Suffixes and prefixes will usually follow vowel harmony rules. Many agglutinative languages have vowel harmony. The term "vowel harmony" is used in two different senses. In the first sense, it refers to any type of long distance assimilatory process of vowels, either "progressive" or "regressive". When used