Andrew J. Lotto
Keith R. Kluender
Lori L. Holt
Dept. of Psychol., Univ. of Wisconsin, Madison, WI 53706
Perception of the voicing contrast in CV syllables can be affected by the duration of the following vowel such that longer vowels lead to more ``voiced'' responses. On the basis of several experiments, Green, Stevens, and Kuhl [Percept. Psychophys. 55, 249--260 (1994)] concluded that continuity of pitch, but not continuity of formant structure, determined the effective length of the following vowel. In attempts to replicate these findings, it was found that both effects were highly dependent upon particular choices of pitch and formant values. First, discontinuity in pitch does not preclude the vowel-length effect when fundamental frequency changes from 200 to 100 Hz and 200-Hz partials extend continuously through test syllables. Second, spectral discontinuity does preclude the vowel-length effect when formant changes result in a spectral peak moving to another harmonic. Even when perceived identity of the vowel remained constant, formant changes that resulted in a change in peak harmonic precluded the vowel-length effect. Yet, changes that did not change peak harmonic and did change perceived vowel identity did not preclude the vowel length effect. Taken together, the results indicate that neither phonemic continuity nor talker continuity, per se, is critical to the vowel-length effect. [Work supported by NSF and NIH.]