How Do 4-Day-Old Infants Categorize Multisyllabic Utterances?

Three experiments, using the high-amplitude sucking procedure. tested whether 4-day-old infants discriminate multisyllabic utterances on the basis of number of syllables or number of phonemes. Experiment 1 showed that infants discriminate 2 large sets of phonetically variable utterances composed of 2vs. 3-CY (consonant-vowel) syllables. Experiment 2 was run to assess whether infants discriminated the 2 sets on the basis of duration differences between the 2and 3-CV stimuli. Results indicate that reducing the duration differences does not affect infants' discrimination. Finally, Experiment 3 investigated whether infants discriminate 4vs. 6-phoneme bisyllabic utterances. The results provide no evidence that infants are sensitive to such a change in number of phonemic constituents. AIthough not decisive, these results appear to be congruent with the hypothesis that infants perceptually structure complex speech inputs.