Fricative-stop coarticulation: acoustic and perceptual evidence

Eight native speakers of American English each produced ten tokens of all possible CV, FCV, and VFCV utterances with V = [a] or [u], F = [s] or [integral of], and C = [t] or [k]. Acoustic analysis showed that the formant transition onsets following the stop consonant release were systematically influenced by the preceding fricative, although there were large individual differences. In particular, F3 and F4 tended to be higher following [s] than following [integral of]. The coarticulatory effects were equally large in FCV (e.g.,/sta/) and VFCV (e.g.,/asda/) utterances; that is, they were not reduced when a syllable boundary intervened between fricative and stop. In a parallel perceptual study, the CV portions of these utterances (with release bursts removed to provoke errors) were presented to listeners for identification of the stop consonant. The pattern of place-of-articulation confusions, too, revealed coarticulatory effects due to the excised fricative context.