An acoustic analysis of the bidirectionality of coarticulation in VCV utterances

Abstract

This study investigated the extent of vowel-to-vowel anticipatory and carry-over coarticulation in VCV utterances. Five speakers of American English produced open (V.CV) and closed (VC.V) syllable shapes with /i/, /ɔ/, /e/ and /u/ as “fixed vowel” contexts and /i/ and /ɔ/ as a “changing vowel” context. Medial consonants were /bdgptk/. Anticipatory coarticulation was indexed by measuring the difference in F 2 offset frequencies for V 1, with a given fixed vowel context, when V 2=/i/ vs. /ɔ/ (e.g., [ibi] vs. [ibɔ]); carry-over coarticulation was indexed by measuring the difference in F 2 onset frequencies for V 2, with a given fixed vowel context, when V 1=/i/ vs. /ɔ/ (e.g., [ibi] vs. [ɔbi]). In open syllables, anticipatory exceeded carry-over coarticulation for labial and velar stops, but carry-over effects predominated in alveolar contexts. Alveolars maximally resist anticipatory effects of V 2 and thus may allow greater V 1 carry-over effects. In closed syllables, carry-over exceeded anticipatory effects across all stops. This was attributed to a short V-to-V temporal interval indexing carry-over effects relative to a disproportionately longer interval separating vowels for anticipatory effects.