Phonetic reduction in spontaneous speech by children aged 9-14 years

The aim of our study was to investigate whether children distinguish between ‘new’ and ‘given’ information via phonetic reduction in spontaneous speech in a similar way to adults. An interactive ‘spot the difference’ game was used to elicit spontaneous speech. Word duration, fundamental frequency and vowel formant frequencies in repeated content words relative to when they were mentioned for the first time were analysed in 96 children between 9-14 years of age. There were significant developmental changes in the three acoustic-phonetic parameters between children and adults. Children produced longer words, had higher median pitch and vowel formant values than adults. However, despite these differences in spontaneous speech between children and adults, we report that, by 9 years of age (and possibly earlier), children produce phonetic reduction to highlight 'new/given' information distinction in spontaneous speech dialogues in an adult-like manner.