In mainland China, around 20,000 infants with non-syndromic cleft lip and/or palate are born every year. There is a great clinical need for the rigorous investigation of the speech problems in this population. This thesis aimed to investigate the consonant misarticulations in native Putonghua speakers with repaired cleft palate based on a research project comprised of four studies. Misarticulations associated with cleft palate are well established for English and several other Indo-European languages. However, few research articles describing the articulation of Putonghua (standard Mandarin Chinese) speakers with cleft palate have been published in English language journals. Study One reviewed relevant studies published over the past 30 years in Chinese language journals. Thirty-seven articles were analyzed and coded on a number of methodological variables. This critical review identified many methodological issues. These design flaws made it difficult to draw reliable conclusions about characteristic articulation errors. Seeing the methodological shortcomings found in Study One, a cross-sectional approach was used in Study Two to identify common consonant error patterns. Thirty-two speakers with repaired cleft palate were allocated to four groups dependent on age and the type of cleft. Articulation was evaluated based on the Putonghua Segmental Phonology Test and the Deep Test for Cleft Palate Speakers in Putonghua. The data were transcribed using International Phonetic Alphabet conventions by two experienced examiners. Several ‘language universal’ findings were identified. In addition, distinctive features in Putonghua phonology appeared to contribute to the observed language specific error patterns. The following two studies focused on the particularly vulnerable manner of articulation: affricates. The results from Study Three showed that distorted affricates from speakers with repaired cleft palate exhibited distinctive spectral features compared to typical articulation. These spectral findings added objective evidence to support the articulation deviation noted in Study Two. Study Four examined the relationship between spectral moments and perceptual judgment of accuracy for the place of affricate and to explore whether listeners relied on different spectral moments to perceive place of articulation. Both typical and distorted affricates were played to twelve listeners to make a judgment of articulation accuracy using visual analog scaling. Results showed that the third spectral moment (L3) was significantly correlated with perceptual rating of accuracy of place information from typical speakers. For affricates produced by speakers with cleft palate, the first moment (M1) showed a significantly correlation with perceptual judgment of the accuracy of alveolar affricates. Recommendations concerning methodological issues in the perceptual investigation of cleft palate speech were given in the systematic review. For the first time, the speech error study demonstrated the influence of language-specific features on Putonghua cleft palate speech. The spectral study contributed to our understanding of the differences in affricate production between speakers with cleft and their typical speaking peers. The investigation of the relationship between spectral features and the perception of alveolar and retroflex affricates provided specific clinical directions for establishing the correct place of articulation. Further research is needed to explore the contribution of other variables (e.g., age of palatoplasty) to the error patterns identified in the present study. / published_or_final_version / Speech and Hearing Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / Community Medicine / Master / Master of Public Health

published_or_final_version / Social Work and Social Administration / Doctoral / Doctor of Philosophy

published_or_final_version / Nursing Studies / Master / Master of Nursing in Advanced Practice

published_or_final_version / abstract / Speech and Hearing Sciences / Master / Master of Science in Audiology

published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Psychology / Master / Master of Philosophy

published_or_final_version / Mental Health / Master / Master of Social Sciences

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Nursing Studies / Master / Master of Nursing in Advanced Practice