Centrals

Centrals, in linguistics, refer to central vowels, the set of vowel sounds produced with the tongue body positioned near the center of the oral cavity. Central vowels lie between front vowels and back vowels, and their height can be mid, near-mid, or close, depending on language. The central region often yields vowels with less contrast than front-back distinctions, resulting in inventories that may be small or large depending on language.

Common examples include the mid central vowel [ə], the schwa, which is frequent in unstressed syllables in many languages; other central vowels include open-mid [ɜ] or [ɜː], and close-mid [ɘ] and [ɵ], as well as high central vowels [ɨ] and [ʉ]. Some languages have rhotacized central vowels, realized as r-colored vowels such as [ɚ] and [ɝ].

Cross-linguistically, centrals are a standard part of many vowel systems, but not all languages contrast central vowels; in some languages the central position is filled by vowels that are analyzed as centralized variants of front or back vowels rather than a distinct central category.

Phonologists study centrals to understand vowel inventories, phonotactics, stress, and vowel harmony. The exact set and articulation of centrals vary by language and dialect, making them a flexible and sometimes fluid category in phonetic transcription.