Synthetic vowels were used to investigate how listeners use vowel duration andformant track shape to determine vowel identity. The synthetic vowels had level or parabolically shaped formant tracks and variable durations. They were presented in isolation as well as in synthetic Consonant-Vowel-Consonant syllables. There was no evidence of perceptual compensatory overshoot for expected target-undershoot due to token duration or context. The only asserted effects of duration and context were in the number of long-and short-vowel responses. There was also no evidence that the listeners used the formant track shape or slopes independently to identify the synthetic vowel tokens. Tokens with curved formant tracks were mainly identified on their formant offset frequencies.