Articulation rate in Swedish child-directed speech increases as a function of the age of the child even when surprisal is controlled for
This research addresses how adults adapt speech for children's linguistic development, providing incremental insights into language acquisition mechanisms.
The study investigated how articulation rate in Swedish child-directed speech (CDS) changes with child age, finding that it increases even after controlling for factors like surprisal, utterance length, and speaker differences, with rates lower for younger children compared to adult-directed speech.
In earlier work, we have shown that articulation rate in Swedish child-directed speech (CDS) increases as a function of the age of the child, even when utterance length and differences in articulation rate between subjects are controlled for. In this paper we show on utterance level in spontaneous Swedish speech that i) for the youngest children, articulation rate in CDS is lower than in adult-directed speech (ADS), ii) there is a significant negative correlation between articulation rate and surprisal (the negative log probability) in ADS, and iii) the increase in articulation rate in Swedish CDS as a function of the age of the child holds, even when surprisal along with utterance length and differences in articulation rate between speakers are controlled for. These results indicate that adults adjust their articulation rate to make it fit the linguistic capacity of the child.