Abstract:
When presented a series of /dVd/ syllables varying perceptually from /d(cursive beta)d/ to /d(inverted vee)d/, listeners identify the vowel sound as /(inverted vee)/ more often than when the vowels are presented alone as steady states. Conversely, /bVb/ series lead to more /(cursive beta)/ identifications. This pattern of responses appears to demonstrate a compensation for assimilatory effects of coarticulation or vowel ``undershoot.'' Experiments will be presented which test the specificity of this perceptual process. Two ten-step (/bVb/ and /dVd/) series of 100-ms /CVC/ syllables varying in F2 midpoint frequency (1260--1710 Hz) were synthesized. Nonspeech analogs were created by appending 70-ms sine-wave glides, which followed a similar trajectory to F2 in the speech stimuli, to 60-ms steady-state vowels varying in F2 frequency. A second set of nonspeech series was created by appending constant-frequency sine-wave tones to the vowel stimuli. The frequency of these tones were set at the F2 starting frequencies for the speech stimuli. These nonspeech contexts had effects on vowel identification that were analogous to those for the speech contexts. Lower frequency glides and tones (modeling /bVb/F2) led to more /(cursive beta)/ (higher F2) identifications with the complementary pattern for higher frequency glides and tones. [Work supported by NIDCD and NSF.]