In phonetics, an allophone is one of several similar speech sounds belonging to a phoneme. Each allophone is the contextually specific implementation of a phoneme.
For example p as in pin and p as in spin are allophones in the English language. English treats these as the same, but they are different. The latter is unaspirated[?] (it sounds a little more like b to an English speaker). Chinese, treats them differently and the latter is written as b in pinyin: thus they are not allophones in Chinese.
In a particular context an habitual approximation of the phonemic ideal usually becomes so familiar as to be conventional.
A phoneme itself, however, is really too abstract and context-variant to have a simple sound wave frequency decomposition. A phoneme as one of the abstract signals of the phonetic system of a language corresponds to a set of similar speech sounds which are perceived by speakers of the language to be a single distinctive sound in that language.
See Phonology, Phonetics, and voice production.
In Quebec, an allophone is a person whose mother tongue[?] is a language other than French (Francophone) or English (Anglophone).
