one of the set of speech sounds in any given language that serve to distinguish one word from another. A phoneme may consist of several phonetically distinct articulations, which are regarded as identical by native speakers, since one articulation may be substituted for another without any change of meaning. Thus /p/ and /b/ are separate phonemes in English because they distinguish such words as pet and bet, whereas the light and dark /l/ sounds in little are not separate phonemes since they may be transposed without changing meaning