Legend: unrounded • rounded 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.
According to PHOIBLE, the most common phonemic back vowel is /u/, occurring in approximately 88% of languages, while the most uncommon phonemic back vowel is /ɒ/, occurring in only 2% of recorded inventories.
Symbols to the right in a cell are voiced, to the left are voiceless.
Shaded areas denote articulations judged impossible.