chroneme (n.)

An abstract unit, used by some PHONOLOGISTS as a means of describing phonologically CONTRASTIVE differences in the LENGTH of speech sounds. Both VOWELS and CONSONANTS may display PHONEMIC contrasts in length: long and short vowels are found in German, long and short consonants in Estonian. The vowel-length differences in English, such as in bit and beat, also involve differences in QUALITY, and the term chroneme is thus not applicable. Those who use this terminology would refer to the ETIC unit of duration as a chrone.