Open central unrounded vowel

The open central unrounded vowel, or low central unrounded vowel, is a type of vowel sound, used in many spoken languages. While the International Phonetic Alphabet officially has no dedicated letter for this sound between front and back, it is normally written $\langle\rangle$. If precision is required, it can be specified by using diacritics, such as centralized $\langle\rangle$ or retracted $\langle\rangle$, but this is not common.

Until recently, however, the letter $\langlea\rangle$ was officially used for the central vowel, and much of the existing body of work on phonetics reflects that. It is thus more common to use plain for a central vowel, and to approximate an open front vowel, if needed, with, officially near-open (near-low). Alternatively, Sinologists may use the unofficial symbol $\langle\rangle$ (small capital A). The IPA voted against officially adopting this symbol in 2011–2012.

The Hamont dialect of Limburgish has been reported to contrast open front, central and back unrounded vowels, which is extremely unusual.

The IPA prefers terms "close" and "open" for vowels, and the name of the article follows this. However, a large number of linguists, perhaps a majority, prefer the terms "high" and "low".