Perceptual centers are affected by stress location in English disyllables

The perceptual centers of English disyllables were investigated in two experiments. Six subjects participated in the first experiment, and five in the second. The first experiment compared initially stressed disyllables with five onsets whose duration varied from 4 (batter) to 180 ms (flatter). Its results demonstrated that initially stressed disyllables with longer onsets have perceptual centers that are displaced relatively further from the acoustic beginning of the word by about the same amount as the difference in the onset durations, in agreement with earlier research on English monosyllables [e.g., A. Cooper, D. Whalen, and C. Fowler, Percept. Psychophys. 39, 187–196 (1986)]. The second experiment compared initially stressed disyllables with disyllables composed of a reduced first syllable and a stressed second syllable, e.g., com’mute vs ’comet, holding the total duration of all items constant. Again, longer onsets produced later perceptual centers for both stress locations, but the perceptual centers of finally stressed disyllables were later than those of initially stressed ones by about 50 ms, or roughly half the duration from the beginning of the unstressed vowel to the beginning of the stressed vowel.