Vowel production and perception: hyperarticulation without a hyperspace effect.
The ability of speakers to exaggerate speech sounds ("hyperarticulation") has led to the theory that the targets themselves must be hyperspace hyperarticulated. Johnson, Flemming, and Wright (1993) found that perceptual "best exemplar" choices for vowels were more speech extreme than listeners' own productions. Our first experiment, using their procedure, only partially replicated their results. Low vowels vowel perception showed a higher F1, consistent with hyperspace. Front vowels also showed more frontness in F2, but back vowels were less extreme ("hypoarticulated") on F2. Our second experiment used an identification and rating of each stimulus, yielding similar results of a smaller magnitude. Our results indicate that the perceptual space is calibrated to a particular (synthetic) vowel space, which is not related straightforwardly to the speakers' spaces. The original hyperspace hypothesis can be attributed to the methodology which led to extreme judgments and of the fronting of back vowels in California English. The present results indicate that no such hypothesis is needed. Vowel targets are measurable from an individual's productions, and the individual's perception of other speakers (even synthetic ones) is based on information about the vocal tract and dialect of the speaker.