Recent work using an attentional allocation paradigm with a phoneme monitoring task has shown that syllabic boundaries preceding stressed syllables are automatically available during online processing of spoken English (Finney et al., 1996). The present research expands on these findings to show that syllabic boundaries preceding unstressed syllables are also available, suggesting that the lack of syllabic effects in earlier syllabic word-fragment monitoring studies (e.g., Cutler et al., 1986) may be due to an interaction of the experimental design and the ambisyllabicity of the materials used. In addition, an experiment using second-syllable stress words to induce expectations about syllabification in first-syllable stress words with the same syllabic structure showed a strong syllabic effect, suggesting that the prelexical syllabic representations used by English listeners are not necessarily contingent on stress. We tentatively argue for a speech perception theory in which syllabic frames organize incoming phonetic features into abstract syllabic units.