A mid vowel is a vowel sound used in some spoken languages. The defining characteristic of a mid vowel is that the tongue is positioned mid-way between an open vowel and a close vowel. The only mid vowel with a dedicated symbol in the International Phonetic Alphabet is the mid central vowel [ə], a symbol which is also used for the vowel schwa.

The IPA divides the vowel space into thirds, with the close-mid vowels such as [e] or [o] and the open-mid vowels such as [ɛ] or [ɔ] equidistant in formant space between open [a] and close [i] or [u]. Thus a true mid front vowel could be transcribed as either a lowered [e̞] or a raised [ɛ̝].

Few languages contrast all three heights of mid vowel, since it is rare for a language to distinguish more than four heights of true front or back vowels. One, the Amstetten dialect of Bavarian German, contrasts four heights of front unrounded, front rounded, and back vowels in addition to having an open central vowel. These have been transcribed with the available IPA symbols /i e ɛ æ/, /y ø œ ɶ/, /u o ɔ ɑ/, and /a/.

	Amstetten Bavarian (transcription)
Close	i	y	u
Close-mid	e	ø	o
Open-mid	ɛ	œ	ɔ
Near open	æ	ɶ̝	ɑ̝
Open		a

However, the vowels transcribed /æ ɶ ɑ/ are one-third the distance between open /a/ and close /i y u/, precisely the IPA definition of open-mid vowels [ɛ œ ɔ]. Thus Amstetten Bavarian may be an example of a language that contrasts mid vowels with both open-mid and close-mid vowels.

	Amstetten Bavarian (formant space)
Close	i	y	u
Close-mid	e	ø	o
Mid	e̞	ø̞	o̞
Open-mid	ɛ	œ	ɔ
Open		a

See also

• Lowered (phonetics)
• Raised (phonetics)