Musicality and Age Interaction in Tone Development

Abstract

Vocal pitch, which involves not only F0 but also multiple covarying acoustic cues is central to linguistic perception and production at various levels of prosodic structure. Recent studies on language development have shown that differences in learners' musicality affect the F0 cue development in perception of sentence-level intonation or in prosodic realization of focus. This study aims to contribute toward a fuller understanding of the effect of musicality on linguistic pitch development via a close investigation of the relationship between musicality, age, and lexical tone production covering both F0 and spectral cues in children. Forty-three native Mandarin-speaking children between the ages of 4 and 6 years are recruited to participate in both a semi-spontaneous tone production task and a musicality test. For each age (4, 5, and 6 years) and musicality (below or above the median score of each age group) group, the contrastivity of the four tones is evaluated by performing automatic tone classification using three sets of acoustic cues (F0, spectral cues, and both). It has been found that higher musicality is associated with higher contrastivity of the tones produced at the age of 4 and 5 years, but not at the age of 6 years. These results suggest that musicality promotes earlier development of tone production only in earlier stages of prosodic development; by the age of 6 years, the musicality advantage in tone production subsides.

Keywords: cue integration; development; musicality; pitch; production; tone.

Figure 1

Performance on PMMA musicality test by age. Raw test scores in percentages are shown in the left panel, and grade-based percentile norm ranks in the right. Kruskal-Wallis test on the raw musicality scores yielded significant variation among different ages, [χ²_{(2,N = 44)} = 6.61, p < 0.05]. A post-hoc Dunn's test with Holm's multiple comparisons adjustment showed that scores of the 4-year-olds and 6-year-olds differed significantly (p < 0.05), but score differences between consecutive age groups were not significant. No significant group differences among the age groups were observed in the percentile norm ranks.

Figure 2

Average tonal classification accuracy from 100 trials of 10-fold cross-validation for each age (4, 5, 6, and 7–8 years) and musicality group (H if median and above, and L if below the median; only available for children between 4 and 6 years of age), using only F0 cues (red solid line), only spectral cues (green dashed line), or both F0 and spectral cues (blue dotted line). Three classification algorithms were tested (LDA: left panel, RF: middle panel, and SVM: right panel).