Effect of fundamental frequency perturbations on medial stop-consonant [voice] judgments

Previous research has suggested that the direction of short-duration fundamental frequency (F0) perturbations following consonants provides a cue to consonant [voice] status. More recently, Silverman [Phonetica 43, 76–91 (1986)] proposed that the [voice] cue is provided by the direction and extent of F0 perturbations relative to the underlying intonational contour. A competing view, the low-frequency hypothesis, suggests that F0 participates in a more general way whereby any low-frequency energy in the region of the consonant will contribute to the perception of a [+ voice] consonant. In this study, 15 speech stimulus series, each ranging perceptually from /aga/ to /aka/, were synthesized by varying VOT from 10 to 45 ms in 5 ms steps. Fifteen different pitch contours were generated by designating F0 targets at three points in the stimulus: initial vowel, onset of voicing energy after closure, and 100 ms after the onset of voicing. Three F0 values were used, arranged into two pairs: 100 and 120 Hz and 120 and 140 Hz. The results indicated that the value of F0 at vowel onset, rather than the relative movement of F0, is the best predictor of subjects’ judgments of consonant [voice] status. [Work supported by NIDCD.]