A back vowel is any in a class of vowel sound used in spoken languages. The defining characteristic of a back vowel is that the highest point of the tongue is positioned relatively back in the mouth without creating a constriction that would be classified as a consonant. Back vowels are sometimes also called dark vowels because they are perceived as sounding darker than the front vowels.
Vowels beside dots are: unrounded • rounded
Near-back vowels are essentially a type of back vowels; no language is known to contrast back and near-back vowels based on backness alone.
The back vowels that have dedicated symbols in the International Phonetic Alphabet are:
- close back unrounded vowel [ɯ]
- close back protruded vowel [u]
- near-close back protruded vowel [ʊ]
- close-mid back unrounded vowel [ɤ]
- close-mid back protruded vowel [o]
- open-mid back unrounded vowel [ʌ]
- open-mid back rounded vowel [ɔ]
- open back unrounded vowel [ɑ]
- open back rounded vowel [ɒ]
There also are back vowels that don't have dedicated symbols in the IPA:
- close back compressed vowel [ɯᵝ] or [uᵝ]
- near-close back unrounded vowel [ɯ̽] or [ʊ̜]
- near-close back compressed vowel [ɯ̽ᵝ] or [ʊᵝ]
- close-mid back compressed vowel [ɤᵝ] or [oᵝ]
- mid back unrounded vowel [ɤ̞] or [ʌ̝]
- mid back rounded vowel [o̞] or [ɔ̝]
As here, other back vowels can be transcribed with diacritics of relative articulation applied to letters for neighboring vowels, such as ⟨u̞⟩, ⟨o̝⟩ or ⟨ʊ̟⟩ for a near-close back rounded vowel.
- Tsur, Reuven (February 1992). The Poetic Mode of Speech Perception. Duke University Press. p. 20. ISBN 978-0-8223-1170-6.
- Scott Moisik, Ewa Czaykowska-Higgins, & John H. Esling (2012) "The Epilaryngeal Articulator: A New Conceptual Tool for Understanding Lingual-Laryngeal Contrasts"