Mid vowel

IPA: Vowels

	Front	Central	Back
Close	i y	ɨ ʉ	ɯ u
Near-close	ɪ ʏ		ʊ
Close-mid	e ø	ɘ ɵ	ɤ o
Mid	e̞ ø̞	ə	ɤ̞ o̞
Open-mid	ɛ œ	ɜ ɞ	ʌ ɔ
Near-open	æ	ɐ
Open	a ɶ	ä	ɑ ɒ

Legend: unrounded • rounded

This article contains phonetic transcriptions in the International Phonetic Alphabet (IPA). For an introductory guide on IPA symbols, see Help:IPA. For the distinction between [ ], / / and ⟨ ⟩, see IPA § Brackets and transcription delimiters.

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 approximately 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.

Vowels

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 ⟨e̞⟩ (with a lowering diacritic) or as a raised ⟨ɛ̝⟩ (with a raising diacritic).^[1]^[2] Typical truly mid vowels are thus:

mid front unrounded vowel [e̞] or [ɛ̝]
mid front rounded vowel [ø̞] or [œ̝]
mid central unrounded vowel [ɘ̞] or [ɜ̝] (most commonly written ⟨ə⟩)
mid central protruded vowel [ɵ̞] or [ɞ̝] (most commonly written ⟨ɵ⟩ as if it were close-mid)
mid central compressed vowel [əᵝ]
mid back unrounded vowel [ɤ̞] or [ʌ̝]
mid back rounded vowel [o̞] or [ɔ̝]

Languages

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.

Kensiu oral vowels
	Front	Central	Back
Close	i	ɯ	u
Near-close	ɪ
Close-mid	e̝	ɚ	o̝
Mid	e	ə	o
Open-mid	ɛ	ʌ	ɔ
Open		a
Diphthongs	ie

Kensiu nasal vowels
	Front	Central	Back
Close	ĩ	ɯ̃	ũ
Near-close	ɪ̃
Close-mid	ẽ̝		õ̝
Mid	ẽ		õ
Open-mid	ɛ̃	ʌ̃	ɔ̃
Open		ã
Diphthongs	ĩẽ

References

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

[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.

[1]

[2]