The aim of this study was to investigate lexical tone production in Cantonese speakers associated with Parkinsonís disease (PD speakers). The effect of intonation on the production of lexical tone was also examined. Speech data was collected from five Cantonese PD speakers. Speech materials consisted of targets contrasting in tones, embedded in different sentence contexts (initial, medial and final) and intonations (statements and questions). Analysis of the normalized F0 patterns showed that PD speakers contrasted the six lexical tones in similar manner as compared with control speakers across positions and intonations, except at the final position of questions. Significantly lower F0 values were found at the 75% and 100% time points of the final syllable of questions for the PD speakers than for the control speakers, indicating that intonation has a smaller influence on the F0 patterns of lexical tones for PD speakers than control speakers. The results of this study supported the previous claim of differential control for intonation and tone.
Bibliographic reference. Ma, Joan Ka-Yin (2009): "Lexical tone production by Cantonese speakers with parkinson's disease", In INTERSPEECH-2009, 1691-1694.