Proceedings of the Annual Meeting of the Cognitive Science Society

This study investigated the differences in speaking rate and fluency between child-directed speech (CDS) and adult-directed speech (ADS), as well as individual variations. We analyzed fluency measures (speaking rate, pausing, repairs, and repetitions) in a corpus of Chinese ADS and CDS. The speech data included forty mothers telling the same story to their 18- or 24-month-old children and an adult. Our findings revealed that: (1) CDS was generally more fluent than ADS, with fewer pauses. (2) There were no significant differences in speaking rate between CDS and ADS for short utterances, but CDS was significantly faster than ADS for longer utterances. (3) We observed age-related differences in speaking rate between 18 and 24 months in relation to utterance length. This suggests that Chinese CDS is not slower but can be faster than ADS. These findings highlight language-specific and individual variations in the temporal aspects of CDS.