Identification of natural and synthetic /dVd/ syllables in two conditions, full and silent center, was compared to investigate the role of dynamic spectral information in the specification of coarticulated American English vowels. Synthetic tokens were generated on a serial formant synthesizer using parameters obtained through a linear predictive coding analysis of the natural tokens. Silent center stimuli were then prepared in the same manner for both natural and synthetic syllables: that portion of the syllable excluding the initial consonant burst and first 40 ms and the last 40 ms before the final consonant closure was attenuated to silence. The original temporal relationship between the 40‐ms parts was not modified. Results of perceptual tests showed that both the natural and synthetic full syllables were well identified with error rates of 2% each. Error rates on the silent‐center tokens, however, were 16% for the natural syllables and 60% for the synthetic, suggesting that synthetic syllables failed to capture important dynamic spectral information available in the syllable onsets and offsets. [Work supported by NIDCD‐00323 and NICHHD‐HD‐01994.]