Page "Phoneme" Paragraph 1

Within linguistics there are differing views as to exactly what phonemes are and how a given language should be analyzed in phonemic terms.

However a phoneme is generally regarded as an abstraction of a set ( or equivalence class ) of speech sounds ( phones ) which are perceived as equivalent to each other in a given language.

For example, in English, the " k " sounds in the words kit and skill are not identical ( as described below ), but they are distributional variants of a single phoneme,.

Different speech sounds representing the same phoneme are known as allophones, such variation may be conditioned, in which case a certain phoneme is realized as a certain allophone in particular phonological environments, or it may be free in which case it may vary randomly.

In this way, phonemes are often considered to constitute an abstract underlying representation for words, while speech sounds make up the corresponding phonetic realization, or surface form.