BACKGROUND: Dysprosody is a common feature in speakers with hypokinetic 
dysarthria. However, speech prosody varies across different types of speech 
materials. This raises the question of what is the most appropriate speech 
material for the evaluation of dysprosody.
AIMS: To characterize the prosodic impairment in Cantonese speakers with 
hypokinetic dysarthria associated with Parkinson's disease, and to determine the 
effect of different types of speech stimuli on the perceptual rating of prosody.
METHODS & PROCEDURES: Speech data in the form of sentence reading, passage 
reading, and monologue were collected from ten Cantonese speakers with 
Parkinson's disease. Perceptual analysis was conducted on ten prosodic 
parameters to evaluate five dimensions of prosody, based on a theoretical 
framework: pitch, loudness, duration, voice quality, and degree of reduction.
OUTCOMES & RESULTS: The results showed that the most severely affected prosodic 
parameters were monopitch, harsh voice, and monoloudness, followed by breathy 
voice and prolonged interval. Differences were noted between speakers with mild 
and moderate dysprosody. No statistically significant differences were found 
between the three types of stimuli. However, qualitative analysis revealed 
noticeable differences between the three stimuli in two speakers.
CONCLUSIONS & IMPLICATIONS: The prosodic profile of Cantonese speakers with 
hypokinetic dysarthria is similar to those of other languages (for example, 
English). The involvement of two new dimensions in the definition of prosody 
(voice quality and degree of reduction) provides additional insight in 
differentiating patients with mild and moderate dysarthria. Further 
investigation on the use of speech materials in the clinical evaluation of 
speech prosody in speakers with dysarthria is needed, as no single task was 
found to represent a patient's performance under all circumstances.