Assibilation

Assibilation is the introduction of sibilance to a sound, to produce a sibilant consonant.

For example, there is a sound change currently in progress in Finnish, where a word-final syllable preceded by a liquid (or even a long vowel) changes to : kielti → kielsi, or by some speakers sääti → sääsi.

The word "assibilation" itself contains an example of the phenomenon. The classical Latin tio was pronounced as (for example, assibilatio was prounounced  and attentio ). In English, it assibilated to (i.e., assibilation became ) and in Italian to  or, as in attenzione and reggio. The process describes a linguistic change in which a consonant followed by or  becomes a sibilant or fricative  with loss of the following  or  (for example, the modern Italian pronunciation of medio as  or .)  The process is probably universal in human languages. There are other interesting, related phenomena--for example piacenza from classical Latin placentia --not only assibilation in the last two syllables (in the Italian form), but the replacement of a liquid for a semi-vowel in the first.