Adaptation to natural fast speech and time-compressed speech in children

Adaptation to artificially time-compressed speech and natural fast speech has been previously shown in adult listeners, with significant improvement of performance within 5-10 sentences. In the present study, we investigated whether typically developing children also adapt to such variations in speech rate. Eighteen children performed a semantic judgment task on normal speed sentences, natural fast sentences and time-compressed sentences. The three speech rate conditions were presented in separate blocks to examine adaptation over exposure time. Analysis of response times broken down into miniblocks of 5 sentences of the same rate reveals that whereas performance for normal sentences remains stable over time, response times become significantly shorter after listening to the first 5 sentences, both in the natural fast and time-compressed conditions. Therefore, children find it more difficult to understand natural fast and time-compressed sentences as revealed by increased response times, but after listening to 5 sentences, their performance improves and becomes comparable to that for normal sentences. These preliminary results suggest that children adapt to speech rate changes as rapidly as adults and that they adapt to both types of speech distortion (natural fast and time compressed) in the same way.