Parallel Processing of Auditory and Phonetic Information in Speech Perception

Abstract

Previous experiments using a variety of techniques have distinguished between separate auditory and phonetic levels of processing in speech perception. For example, Day and Wood [J. Acoust. Soc. Am. 51, 79(A) (1972)] showed that an auditory dimension of synthetic syllables could be processed independently of a phonetic dimension, but that the phonetic dimension could not be processed independently of the auditory dimension. Two models of auditory and phonetic processing appear to be consistent with these results: (1) a serial model in which auditory information would be processed at one level followed by the processing of phonetic informational a subsequent level; (2) a parallel model in which the processing of auditory and phonetic information could be initiated and proceed simultaneously. The present experiment attempted to distinguish empirically between these two models. Subjects identified either an auditory dimension (fundamental frequency) or a phonetic dimension (place of articulation of the consonant) of synthetic consonant-vowel syllables. When the two dimensions varied in a completely correlated manner, reaction times were significantly shorter than when either dimension varied alone. These results are consistent only with a model in which auditory and phonetic information can be processed in parallel.