Speech Production Development in Mandarin-Speaking Children: A Case of Lingual Stop Consonants.

Lingual stops are among the earliest sounds acquired by young children, but the process of acquiring the temporal coordination of lingual gestures necessary for the production of stop consonants appears to be protracted. The current research aims to investigate the developmental process of lingual stop consonants in 100 Mandarin-speaking 2- to 5-year-olds using the acoustic parameter voice onset time (VOT). Children were engaged in a word-repetition task and recorded while producing words that begin with /t/, /d/, /k/, and /g/. Results indicate well-established contrasts between /t/ and /d/ as well as between /k/ and /g/ by age 2. However, comparing with adults' speech patterns, children's speech productions are characterized by greater within-category dispersion and overlap, as well as smaller phoneme discriminability. Mandarin-speaking children also go through an "overshoot" stage by producing longer-than-adult VOT values, especially for voiceless aspirated stops /t/ and /k/. Lastly, unlike adults who exhibit gender-specific patterns in VOT, boys and girls do not show distinct patterns in their VOT by age 5. These results will be discussed in relation to children's lingual motor control development and the organization of phonological and phonetic structures during the process of language acquisition.