Acoustic development of vowel production in native Mandarin-speaking children

Abstract

The present study aims to document the developmental profile of static and dynamic acoustic features of vowel productions in monolingual Mandarin-speaking children aged between three and six years in comparison to adults. Twenty-nine monolingual Mandarin children and 12 native Mandarin adults were recorded producing ten Mandarin disyllabic words containing five monophthongal vowel phonemes /a i u yɤ/. F1 and F2 values were measured at five equidistant temporal locations (the 20–35–50–65–80% points of the vowel's duration) and normalized. Scatter plots showed clear separations between vowel categories although the size of individual vowel categories exhibited a decreasing trend as the age increased. This indicates that speakers as young as three years old could separate these five Mandarin vowels in the acoustic space but they were still refining the acoustic properties of their vowel production as they matured. Although the tested vowels were monophthongs, they were still characterized by distinctive formant movement patterns. Mandarin children generally demonstrated formant movement patterns comparable to those of adult speakers. However, children still showed positional variation and differed from adults in the magnitudes of spectral change for certain vowels. This indicates that vowel development is a long-term process which extends beyond three years of age.