Consonance is a stylistic evice, often used in poetry characterized by the repetition of two or more consonants using different vowels, for example, the "i" and "a" followed by the "tter" sound in "pitter patter." It repeats the consonant sounds but not vowel sounds. This is not to be confused with Assonance. Assonance is the repetition of only vowel sounds. Alliteration differs from consonance insofar as alliteration requires the repeated consonant sound to be at the beginning of each word, where in consonance it is anywhere within the word, although often at the end. In half rhyme, the terminal consonant sound is repeated. A special species of consonance is using a series of sibilant sounds (/s/ and /sh/ for example); this is sometimes known simply as sibilance.