Articulation rate in child-directed speech increases as a function of child age

It has been shown that articulation rate (AR), the number of produced linguistic units per time unit with pauses excluded, is lower in child-directed speech (CDS) than in adult-directed speech (ADS). The present study is the first corpus-based longitudinal study to investigate AR in Swedish CDS as a function of child age while also control-ling for utterance length in terms of number of syllables and for individual differences between speakers. AR in transcribed utterances of 7 parents directed at their respective child during different ages was analyzed with mixed effects modeling. Results show a signif-icantly higher AR in longer than in shorter utterances and a significant increase in AR as a function of infant age. Future studies include comparison with entropy-based measures