聲調在中文具有辨義的功能，而聽障孩童由於在接收自己和他人所發出的語音回饋時有缺損，因而導致聲調學習上的困難。本研究探討學齡前聽障幼童與同年齡正常聽力幼童間聲調習得上的差異，及聲調發音特質的不同。本研究分成兩個部分，分別是長期研究一位聽障孩童（從2歲5個月至3歲5個月），及研究同年齡範圍聽障及聽常孩童各6位。我們分別以聲調錯誤率、出現率及聲學特質來分析比較聽障及聽常孩童聲調發音的不同。在聲調錯誤率方面，發現一聲的錯誤率最低，四聲的出現率最高。一聲四聲常互相取代，二聲三聲也常互相取代。至於聲學分析方面，發現聽障幼童聲調時長過長、聲調曲線較為平緩。

Tones in Mandarin Chinese are essential for determining lexical meanings. Lacking sufficient auditory feedback, Mandarin-speaking hearing-impaired children may have a hard time mastering tones. The present study aims to examine the differences between the acoustic tonal values of the tones produced by hearing-impaired children of pre-school age and those produced by children of the same age with normal hearing. One hearing-impaired child participated in longitudinal observation (from 2 years and 5 months to 3 years and 6 months), and six hearing-normal and six hearing-impaired children were recruited in the cross-sectional study. Tone productions were measured at the beginning point, middle point, end point, inflectional point, slope, and duration. Results showed that tone productions of the hearing-impaired children were exceptionally long in duration, abnormally high in fundamental frequency, and flat in contour patterns.