PHONEME

PHONEME. In PHONETICS and LINGUISTICS, the basic theoretical unit of distinctive sound in the description of SPEECH, out of which syllables are formed, such as the three units /b, I, t/ (consonant, vowel, consonant) in /bit/ (bit). The OED (1989) defines the phoneme as ‘A phonological unit of language that cannot be analysed into smaller linear units and that in any particular language is realized in non-contrastive variants’. The Longman Dictionary of Applied Linguistics (1985) defines the phoneme as ‘the smallest unit of sound in a language which can distinguish two words’, giving the examples pan and ban, that differ only in the contrast of the phonemic consonants /p/ and /b/, and ban and bin, that differ only in the phonemic vowels /æ/ and /I/. The number of phonemes varies from language to language, and from variety to variety within a language. Any such number, as for example the 24 consonants and 20 vowels of RP, are known as a phoneme inventory. A PHONE is a realization in sound of a phoneme, and an allophone is one such realization among others: for example, English /n/ is normally alveolar, but is dental before the dental fricative /ɵ/ in tenth [tɛnɵ]. There are no minimal pairs contrasting dental and alveolar [n], and so the difference is not phonemic: because of this, the two forms are said to be allophones of the same phoneme /n/. When allophones occur in different environments, only one over occurring in one environment, they are said to be in complementary distribution. The term allophone is also used to include the free variant, a sound that can be substituted for another without bringing about a change of meaning. Examples include the various r-sounds of English and the use of the GLOTTAL STOP as a variant of [t] in a word like water. See BLOOMFIELD, -EME, MINIMAL PAIR.