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 ,
Strident vowel Bai, of southern China, has a register system that has allophonic strident and pressed vowels. There is no official symbol for stridency in the IPA, but a superscript (for a voiced epiglottal trill) is often used. In some literature, a subscript double tilde (≈) is sometimes used, as seen here on the letter (): It has been accepted into Unicode, at code point U+1DFD. Strident vowel Strident vowels (also called sphincteric vowels) are strongly-pharyngealized vowels accompanied by (ary)epiglottal trill, with the larynx being raised and the pharynx constricted. Either the epiglottis or the arytenoid cartilages thus vibrate instead of the