segment (n.)

A term used in PHONETICS and LINGUISTICS primarily to refer to any DISCRETE UNIT that can be identified, either physically or auditorily, in the stream of speech. Segmentation can take place using either physical or auditory criteria: in the former case, ACOUSTIC or ARTICULATORY change-points can be identified as boundaries of segments; in the latter case, perceptible changes in QUALITY or QUANTITY, often showing the influence of the language’s PHONEMIC units, are the basis of division. The term is especially used in phonetics, where the smallest perceptible discrete unit is referred to as a PHONE. A feature which begins or ends within one of the phases of articulation of a segment is called a subsegmental feature. ‘Segment’ has developed an abstract sense in GENERATIVE PHONOLOGY, where it is used for a mental unit of phonological organization – one of a series of minimal units which, however, are not strung together in a simple LINEAR way. In this model, no physical reality is being segmented.

In phonology, a major division is often made into segmental and SUPRASEGMENTAL (or non-segmental) categories. Segmental phonology analyses the speech into distinctive units, or PHONEMES (= ‘segmental phonemes’), which have a fairly direct correspondence with phonetic segments (alternative approaches involve analysis in terms of DISTINCTIVE FEATURES and PROSODIES). Suprasegmental or non-segmental phonology analyses those features of speech which extend over more than one segment, such as INTONATION or (in some theories) VOWEL harmony.

The above terminology has been applied analogously to the study of written texts, where GRAPHS and GRAPHEMES are some of the segments identified. The term is also found in the analysis of higher linguistic units, such as MORPHEMES or WORDS, as in STRUCTURALIST analyses of GRAMMAR. In GENERATIVE SYNTAX, a segment refers to each layer of the same label created in Chomsky-ADJUNCTION structure; the notion is used in association with CATEGORY.