harmony (n.)

A term used in PHONOLOGY to refer to the way the ARTICULATION of one phonological UNIT is influenced by (is ‘in harmony’ with) another unit in the same WORD or PHRASE. An analogous notion is that of ASSIMILATION.

The two main processes are consonant harmony and vowel harmony. In the typical case of VOWEL harmony, for example, such as is found in Turkish or Hungarian, all the vowels in a word share certain FEATURES – for instance, they are all articulated with the FRONT of the TONGUE, or all are ROUNDED. The subsets of vowels which are affected differently by harmonic processes are harmonic sets. Disharmony (or disharmonicity) occurs when a vowel from set A is used (e.g. by SUFFIXATION) in words which otherwise have set B, thus forming a harmonic island (if TRANSPARENT) or a new harmonic span (if OPAQUE). The span within which harmony operates (usually the word) is the harmonic domain.

In OPTIMALITY THEORY, the measurement of the overall goodness of a FORM given a CONSTRAINT RANKING.