Vowels as Islands of Reliability.

Vowel nuclei of syllables appear to provide a relatively stable (although not stationary) frame of reference for judging consonant events. We offer evidence that reliable consonant identification demands prior or simultaneous evaluation of this "vocalic frame." Listeners were presented a list of /bVs/, /dVs/, and /gVs/ syllables and were instructed to press a response key immediately upon recognizing a particular initial consonant target. Three groups of subjects monitored for /b/, /d/, and /g/, respectively. The test syllables contained 10 English vowels varying substantially in intrinsic duration. Response times to the initial consonants correlated positively with the duration of the following vowels, even when the effect of consonant-vowel formant transition duration was partialed out. The results suggest that consonant recognition is vowel dependent and, specifically, that a certain amount or proportion of the vowel formant trajectory must be evaluated before consonants can be reliably identified.