A preliminary to this supplanting of phonemes by a set of unit-length components is the classification of phonemes by the speech feature representations which they have in common. In this classification, each phoneme is considered as representing a combination of articulatory or acoustic speech features (e.g./p/ may be considered to represent a labial position and a stop articulation), and a given feature is represented by several phonemes ( e.g. /f/ may represent labial position with continuant articulation). Such classification becomes of interest to the descriptive linguistic analysis of a particular language only when it is based not on absolute phonetic categories (such as particular tongue positions, or even tongue position in general), but on relative categories determined by the differences among the phonemes of that language.
- Harris (1951), Pag. 146