äänneharmoniaa

Äänneharmoniaa, often translated as vowel harmony, is a phonological process found in many languages where vowels within a word assimilate to each other in terms of certain phonetic features. Typically, this assimilation involves backness (front vs. back vowels) and roundedness (rounded vs. unrounded vowels). For example, in Turkish, a language well-known for its vowel harmony, suffixes change their vowel to match the vowel in the root word. If the root word has front vowels like 'e', 'i', 'ö', 'ü', the suffixes will also use front vowels. If the root has back vowels like 'a', 'ı', 'o', 'u', the suffixes will use back vowels.

The specific rules and the features that undergo harmony vary greatly between languages. Some languages have harmony based on only one feature, while others incorporate multiple features. The phenomenon can also be bidirectional, meaning that vowels can influence preceding vowels as well as succeeding ones, though this is less common. Äänneharmoniaa plays a significant role in the sound system and morphology of languages that possess it, contributing to a distinct auditory quality and simplifying the grammatical marking of words. It is a key characteristic studied in phonology and comparative linguistics.