High Quality Content by WIKIPEDIA articles! Consonant mutation is the phenomenon in which a consonant in a word is changed according to its morphological and/or syntactic environment. Mutation phenomena are found in languages around the world. The prototypical example of consonant mutation is the initial consonant mutation of all modern Celtic languages. Initial consonant mutation is also found in Indonesian or Malay, in Southern Paiute and in several West African languages such as Fula. The Nilotic language Dholuo, spoken in Kenya, shows mutation of stem-final consonants, as does English to a small extent. Mutation of initial, medial, and final consonants is found in Modern Hebrew. Japanese exhibits word medial consonant mutation involving voicing, rendaku, in many compounds.