Development of Phonetic Contrasts in Cantonese Tone Acquisition.

Purpose Previous studies showed both early and late acquisition of Cantonese tones based on transcription data using different criteria, but very little acoustic data were reported. Our study examined Cantonese tone acquisition using both transcription and acoustic data, illustrating the early and protracted aspects of Cantonese tone acquisition. Method One hundred fifty-nine Cantonese-speaking children aged between 2;1 and 6;0 (years;months) and 10 reference speakers participated in a tone production experiment based on picture naming. Natural production materials with 30 monosyllabic words were transcribed by two native judges. Acoustic measurements included overall tonal dispersion and specific contrasts between similar tone pairs: ratios of average fundamental frequency height for the level tones (T1, T3, T6), magnitude of rise and inflection point for the rising tones (T2, T5), magnitude of fall, H1*-H2*, and harmonic-to-noise ratio for the low tones (T4, T6). Auditory assessment of creakiness for T4 was also included. Results Children in the eldest group (aged 5;7-6;0) were still not completely adultlike in production accuracy, although two thirds of them had production accuracy over 90%. Children in all age groups had production accuracy significantly higher than chance level, and they could produce the major acoustic contrasts between specific tone pairs similarly as reference speakers. Fine phonetic detail of the inflection point and creakiness was more challenging for children. Conclusion Our findings illustrated the multifaceted aspects (both early and late) of Cantonese tone acquisition and called for a wider perspective on how to define successful phonological acquisition. Supplemental Material https://doi.org/10.23641/asha.11594853.