schwa

Schwa is a term in phonetics for a mid-central, neutral vowel sound that often occurs in unstressed syllables. In the International Phonetic Alphabet it is represented by the symbol ə. Schwa is not tied to a single language or phoneme; rather, it denotes a class of vowel sounds realized in different ways across languages.

In English, schwa is the typical reduced vowel in unstressed syllables and is heard in words such as about and pencil. In American English the rhotacized variant ɚ is used in some unstressed syllables, as in "letter."

Phonetically, schwa is typically mid or near-mid in height and central in backness; the exact quality varies across languages. It is usually short and reduced in connected speech. Some languages have multiple reduced vowels; in others schwa merges with surrounding vowels or disappears in rapid speech.

Not all languages use a distinct schwa as a phoneme. In many languages schwa is an allophone of other vowels or a feature of reduced-stress pronunciation rather than a separate sound. The symbol ə is used in IPA for the central relaxed vowel, and related symbols such as ɚ and ɝ denote rhotacized variants in American English.

Origin of the term: the name schwa comes from the Hebrew shəwā meaning "empty" or "neutral", and was transmitted through German scholarly usage.