The most commonly seen types of umlaut are the following: • Vowel raising, triggered by a following
high vowel (often specifically a high front vowel such as /i/) as in Kannada. • Vowel fronting, triggered by a following
front vowel (often specifically a high front vowel such as /i/), as in German. • Vowel lowering, triggered by a following non-high vowel (often specifically a
low vowel such as /a/), as in Spoken Tamil. • Vowel rounding, triggered by a following rounded vowel (often specifically a high rounded vowel such as /u/), as in
Icelandic. All of these processes occurred in the history of the
Germanic languages; see
Germanic umlaut for more details.
I-mutation is the most prominent of the processes, to the extent that it is often referred to simply as "umlaut". Similar processes also occurred in the history of the
Celtic languages, especially
Old Irish. In this context, these processes are often referred to as
affection. Vowel-raising umlaut occurred in the history of many of the
Romance languages, in the study of which it is normally termed
metaphony. ==See also==