Phonological changes in syllable duration and filler syllables in early child language



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This study investigated the development of prosody in American English and its relationship to segmental phonology and morphology with a focus on the acquisition of stress patterns. The data were collected from a male child by his father from 1;4 to 4;4 biweekly. Of these, twelve data points between 18 and 23 months were analyzed (approximately 30 minutes each). All utterances were coded into one of the following categories using transcriptions, notes, and audio data: Monosyllabic, Filler plus Monosyllabic, Disyllabic, Filler plus Disyllabic, Multisyllabic, and Filler plus Multisyllabic.

The total number of utterances and syllables per utterance increased from 18 to 23 months. At 18 months, only 35% (84/236) of the child’s utterances were multisyllabic, while 72% (612/851) such utterances were produced at 23 months. At 18 months, 20% of the utterances (48/236) contained filler syllables. Between 21_2 and 22_0 months, the number of filler syllables decreased suddenly. At 22 and 23 months, the child produced filler syllables again, but this time with disyllabic and multisyllabic words.

The disyllables were coded into one of the following: trochaic, iambic, or evenly stressed, then acoustic analysis was conducted on duration of those disyllables. A total of 160 utterances were measured. The results indicate that the second syllable was in general longer than the first syllable and the difference between first and second syllables was not significant at 21 months, whereas it was significant at 18 and 23 months.

These findings suggested that 21 months was an important milestone in language development for this child. At 21 months, the number of filler syllables decreased and the duration of syllables showed a different pattern from 18 and 23 months. These data suggested that there may have been a change in this child’s phonology at 21 months.



Prosody in American English (PAE), Prosody, Syllable stress, Language acquisition