In
phonetics, 'length' or 'quantity' is a
feature of sounds that are distinctively longer than other sounds. There are
long vowels as well as
long consonants (the latter are often called ''geminates'').
Many languages do not have distinctive length. Among the languages that have distinctive length, there are only a few that have both distinctive vowel length and distinctive consonant length. It is more common that there is only one or that they depend on each other.
The languages that distinguish between different lengths have usually long and short sounds. According to some linguists,
Estonian and some
Sami languages have three phonemic (meaning-distinguishing) lengths for consonants and vowels.
Strictly speaking, a pair of a long sound and a short sound should be identical except for their length. In certain languages, however, there are pairs of
phonemes that are traditionally considered to be long-short pairs even though they differ not only in length, but also in quality, for instance
English "long e" which is (as in ''w'ee'd'' ) vs. "short e" which is (as in ''w'e'd'' ) or
German "long e" which is (as in ''B'ee't'' 'garden bed') vs. "short e" which is (as in ''B'e'tt'' '(sleeping) bed'). Also, tonal contour may reinforce the length, as in Estonian, where the over-long length is concomitant with a tonal variation resembling tonal stress marking.
In non-linear
phonology, the feature of length is often not a feature of a specific sound segment, but rather of the whole syllable.
See also
Chroneme.