The Nature and Function of Phonetic Categories
The distinction between auditory and phonetic processes in speech perception is an old one. But only have students discovered its theoretical worth. From a linguistic point of view, the function of segmental phonetic categories is to serve as the finite set of commutable elements of which language will make infinite use. The perceptual function of phonetic categories is then, on the one hand, to forestall auditory babble, on the other, to store information derived from the signal until such time as it can be granted a linguistic interpretation. Study of sound spectrograms reveals that portions of the acoustic patterns for related phonetic segments often lie along an apparent acoustic continuum. K. N. Stevens remarked the brief, transient nature of stop consonant acoustic cues, and showed, as did R. H. Sachs, that vowels were more categorically perceived if their duration and acoustic stability were reduced by placing them in CVC syllables.