Close Back Unrounded Vowel

The close back unrounded vowel, or high back unrounded vowel, is a type of vowel sound used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɯ⟩. Typographically a turned letter m, given its relation to the sound represented by the letter u it can be considered a u with an extra "bowl". The sound is sometimes referred to as "unrounded u".

The IPA prefers terms "close" and "open" for vowels, hence the name of this article. However, a large number of linguists, perhaps a majority, prefer the terms "high" and "low", and these are the only terms found in introductory textbooks on phonetics such as those by Peter Ladefoged.