A mid vowel (or a true-mid vowel) is any in a class of vowel sounds used in some spoken languages. The defining characteristic of a mid vowel is that the tongue is positioned midway between an open vowel and a close vowel.

Other names for a mid vowel are lowered close-mid vowel and raised open-mid vowel, though the former phrase may also be used to describe a vowel that is as low as open-mid; likewise, the latter phrase may also be used to describe a vowel that is as high as close-mid.



The only mid vowel with a dedicated symbol in the International Phonetic Alphabet is the mid central vowel with ambiguous rounding [ə].

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] or [ɒ] and close [i] or [u]. Thus a true mid front unrounded vowel can be transcribed as either a lowered ⟨⟩ (with a lowering diacritic) or as a raised ⟨ɛ̝⟩ (with a raising diacritic).[1][2] Typical truly mid vowels are thus:



Few languages contrast all three heights of mid vowel, because it is rare for a language to distinguish more than four heights of true front or back vowels.

The Kensiu language spoken in Malaysia and Thailand is highly unusual in that it phonemically contrasts true-mid vowels with close-mid and open-mid vowels without differences in other parameters such as backness or roundedness.


  1. ^ Wayland, Ratree (2018). Phonetics: A Practical Introduction. Cambridge: Cambridge University Press. p. 26. ISBN 978-1-10841-834-8.
  2. ^ Rogers, Henry (2000). The Sounds of Language: An Introduction to Phonetics. Harrow: Longman. p. 9. ISBN 978-1-31787-775-2.