Auditory representations and phonological illusions: A linguist’s perspective on the neuropsychological bases of speech perception

Abstract

This paper argues that speech perception includes grammatical—in particular phonological—computations implemented by an analysis-by-synthesis component (Halle & Stevens, 1962) which analyzes linguistic material by synthesizing it anew. Analysis-by-synthesis, however, is not always required in perception but only when the listener wants to be certain that the words or morphemes identified in the input signal correspond to those intended by the speaker who produced the signal (= parity requirements, see Liberman, 1996, Liberman and Whalen, 2000). As we will see, in some situation analysis-by-synthesis may generate ‘phonological’ illusions. A central assumption is that the representations of words or morphemes in perception involve distinctive features and are formally structured into syllables. Two perceptual modes are needed: phonetic and phonemic perception. In phonemic perception only contrastive aspects of sounds, i.e., the aspect of sounds associated with meaning differences, are searched for. In phonetic perception both contrastive and noncontrastive aspects of sounds are identified. The phenomenon of phonological ‘deafening’ will be shown to follow from phonemic perception.