Metaphony

In historical linguistics, metaphony is a general term for a class of sound change in which one vowel in a word is influenced by another in a process of assimilation.

Progressive metaphony, in which a vowel early in the word influences a subsequent vowel, can be distinguished from regressive metaphony, in which a vowel towards the end of the word influences a preceding vowel. (Progressive metaphony is sometimes called "left-to-right" metaphony, and regressive metaphony may be called "right-to-left" metaphony.)

Progressive metaphony is also called vowel harmony, and is discussed fully in the article under that heading. However, some linguists use the term "vowel harmony" for regressive metaphony too.

Examples of regressive metaphony are i-mutation and a-mutation. (On i-mutation in Germanic languages see also Germanic umlaut.)

See also