Acoustic Analysis of Preschool Children's Speech

In this paper, changes in acoustic characteristic of young children speech are investigated as a function of age. We examined fundamental frequency, formant frequencies and vowel durations of ten monophtongal vowels from American-English speaking children, age groups 3 to 6. In this study, we also examined the vowel pronunciation variability of young-aged children. The results show that preschool children speech exhibits high fundamental and formant frequencies and greater variations between subjects for all age groups. Individual vowel durations averaged across all subjects in preschooler follows similar pattern for all age groups. Our statistical analysis shows that age effect is significant on pronunciation variability. Finally, an information-theoretic analysis of developmental changes in the speech signal is presented. The findings based on mutual information between the vowel category and the spectral features correspond well with results of automatic vowel recognition.