Acquisition of English Speech Rhythm by Monolingual Children

We investigated how English rhythmic patterns develop in the course of first language acquisition by children between four and twelve years. We have empirically confirmed that rhythm becomes increasingly more stress-timed as acquisition progresses, which is revealed by higher durational variability of syllables, vocalic sequences and consonantal clusters in speech delivered by older children compared to younger children. The development of speech rhythm was studied using the same speech material produced by children at various ages, while controlling for the differences in phonotactics and syllable structure. The tendency to deliver speech with higher durational variability at later stages of language acquisition emerges even when the phonological differences in speech material inevitable in uncontrolled speech delivered by children of different ages are controlled for. This finding indicates that the language-specific phonetic timing patterns are established as a function of age, probably as a result of the motor control development.