DISTINCTIVE FEATURES AND ESL PHONOLOGY
The definition and classification of distinctive features
Distinctive feature: "In phonology, a particular characteristic which distinguishes one distinctive sound unit of a language from another or one group of sounds from another group" (Richards, Platt & Platt, 1992, p. 114). The term refers to "a minimal contrastive unit recognized by some linguists as a means of explaining how the sound system of languages is organized. Distinctive features may be seen either as part of the definition of phoneme (Prague School) or as an alternative to the notion of the phoneme" (Crystal, 1991, p. 109). Distinctive phonological features--such as voicing, tongue-height, and lip rounding--are identified through "an analysis of vowels and consonants in terms of a set of additive components within a single phonetic framework" (Crystal, 1992, p. 300). Usually, features are grouped into four main classes, relating to places of articulation, types of stricture, the oral/nasal process, and laryngeal activity.
Examples of one phoneme (distinctive sound) from another: the presence of the feature voice distinguishing /b/ (as in bin) from /p/ (as in pin) and /d/ from /t/. The /b/ is a voiced stop, whereas the /p/ is a voiceless stop. Vowels and sounds such as /l/, /n/, and /m/, where the air passes relatively freely through the mouth and nose, have the feature [+sonorant], whereas sounds such as /p/, /k/, and /s/, where the air is stopped either completely or partially, have the feature [-sonorant].
Phonemic analysis will thus identify /p/ and /b/ as, respectively, voiceless and voiced, but as both bilabial, plosive, oral, and pulmonic egressive. On the other hand, /p/ and /g/ differ in contrast of voicing and in the place of articulation--bilabial vs. velar. And /p/ and /z/ differ in the manner of articulation (plosive vs. fricative), and in the contrasts of voicing and place.
All segments can be analyzed ...