Vowel length

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In linguistics, vowel length is the perceived length of a vowel sound; the corresponding physical measurement is duration. Vowels perceived as shorter are often described as short vowels and those perceived as longer as long vowels.

On one hand, many languages do not distinguish vowel length phonemically, meaning that vowel length alone does not change the meanings of words. However, the amount of time a vowel is uttered can change based on factors such as the phonetic characteristics of the sounds around it, the phonetic environment, for instance whether the vowel is followed by a voiced or a voiceless consonant. On the other hand, vowel length is indeed an important phonemic factor in certain languages, meaning vowel length can change word-meanings, for example in Arabic, Czech, Dravidian languages (such as Tamil), some Finno-Ugric languages (such as Finnish and Estonian), Japanese, Kyrgyz, Samoan, and Xhosa. Some languages in the past likely had the distinction even though their modern descendants do not, with an example being Latin versus its descendent Romance languages like Spanish and French. Length also plays a lesser phonetic role in Cantonese, unlike in other varieties of Chinese, which do not have phonemic vowel length distinctions.

Whether vowel length alone changes word-meanings in English depends on the particular dialect; it is able to do so in a few non-rhotic dialects, such as Australian English, Lunenburg English, New Zealand English, South African English, and possibly some Southern British English. For instance, vowel length can distinguish park /paːk/ from puck /pak/ in Australian and New Zealand English, or bared /beːd/ from bed /bed/ in any of these dialects. Phonemic vowel length perhaps marginally occurs in a few rhotic dialects too, such as Scottish English and Northern Irish English (see Scottish vowel length rule).

Languages that do distinguish vowel length phonemically usually only distinguish between short vowels and long vowels. Very few languages distinguish three phonemic vowel lengths; some that do so are Estonian, Luiseño, and Mixe. However, languages with two vowel lengths may permit words in which two adjacent vowels are of the same quality: Japanese ほうおう, hōō, "phoenix", or Ancient Greek ἀάατος [a.áː.a.tos],^[1] "inviolable". Some languages that do not ordinarily have phonemic vowel length but permit vowel hiatus may similarly exhibit sequences of identical vowel phonemes that yield phonetically long vowels, such as Georgian გააადვილებ, gaaadvileb [ɡa.a.ad.vil.eb], "you will facilitate it".