In linguistics, vowel length is the perceived duration of a vowel sound. Often the chroneme, or the "longness", acts like a consonant, and may have arisen from one etymologically, such as in Australian English. While not distinctive in most other dialects of English, vowel length is an important phonemic factor in many other languages, for instance in Finnish, Fijian, Japanese, Old English, and Vietnamese. It plays a phonetic role in the majority of dialects of British English, and is said to be phonemic in a few other dialects, such as Australian English, South African English and New Zealand English. It also plays a lesser phonetic role in Cantonese, unlike other varieties of Chinese.