In linguistics, a chroneme is an abstract phonological suprasegmental feature used to signify contrastive differences in the length of speech sounds.
[1] The noun chroneme is derived from Ancient Greek χρόνος (khrónos) 'time', and the suffixed -eme, which is analogous to the -eme in phoneme or morpheme.
[3] The term is not widely used today, and in the case of English phonetics, Jones' analysis of long and short vowels (e.g. the /iː/ of bead and the /ɪ/ of bit ) as distinguished only by the chroneme is now described as "no longer tenable".
For example, in Italian: or Sicilian: Distinctive length in vowels may be presented by the cŭ + cū minimal pair in the dialect spoken near Palmi, Calabria (Italy): A number of Uralic languages, such as Finnish, Hungarian and Estonian have a distinctive moraic chroneme as a phoneme (also arguably called archiphoneme).
Estonian, in which the phonemic opposition is the strongest, uses tonal contour as a secondary cue to distinguish the two; "over-long" is falling as in other Finnic languages, but "half-long" is rising.
Finnish also denotes stress principally by adding more length (approximately 100 ms) to the vowel of the syllable nucleus.
Hence, among other contrasts, the word hik-ki is felt to be one mora or beat longer than hi-ki by a speaker of Japanese.