the phonetic uniformity between the root and affixes in a word, consisting in the equalization of the vowels or, sometimes, the consonants of a word with respect to some phonetic feature, such as the point of stricture (front back), labialization (rounding), or height. In Hungarian, for example, the vowel in the allative affix haz/höz is either a front or a back vowel depending on the vowel in the nominal root: ablak-haz, “toward the window,” and küszöb-höz, “toward the threshold.” Synharmony is a feature principally of agglutinative languages, for example, the Turkic, Finno-Ugric, Mongolian, Manchu-Tungus, some West African, and Paleo-Asiatic languages.
As does stress in inflected languages, synharmony imparts a unity to the components of a word, signaling the word’s integrity and separateness; it usually does not occur in compound words. In many languages that feature synharmony, the vowels e and i are neutral and may occur in words with both front and back vowels. Some scholars compare synharmony with the umlaut in the Germanic languages; however, the umlaut resembles synharmony only phonetically, not functionally. Synharmony is also often equated with vowel harmony, although the former also includes consonant harmony, as in some languages of North America and Oceania. Synharmony is a suprasegmental phenomenon.
V. A. VINOGRADOV