A series of experiments investigated infants' perception of inherent structural organization in the prosody of utterances. The experiments used a listening preference procedure to test: perceptions of appropriate pauses in child-directed and adult-directed speech; perceptions of appropriate pauses in speech filtered for most segmental features but leaving prosodic features intact; and the role of experience in infants' sensitivity to prosodic cues and clausal units, by exposing the native English-speaking children to Polish speech. Infants in the English-language experiments were aged 6 to 12 months, and the infants in the Polish-language experiments were aged 4-and-a-half and 6 months. The study presents results and discusses them in relation to research on children's perceptions of music. (MSE)