Title : Prosodic changes in patients with idiopathic parkinson’s disease: The effect of dysarthria severity
Abstract:
Background & Objective: Patients with Parkinson’s disease frequently show hypokinetic dysarthria exhibiting both segmental and suprasegmental features of speech, such as monotonous pitch, reduced intensity, inappropriate pauses, slow or fast speech rate, and harsh voice. Prosody is suprasegmental aspects of speech that we use to communicate, emphasize, or revise the meaning of a speaker’s message. The purpose of this study is to investigate prosodic characteristics in patients with idiopathic Parkinson’s disease (IPD) during oral reading and elucidate changes in speech along with dysarthria severity.
Methods: We collected data from 105 patients with IPD aged from 43 to 82 for this study. The patients were divided into 4 groups of mild, moderate, severe, and profound according to dysarthria severity. Each participant was asked to read the whole passage “autumn” composed of nine sentences. For acoustic analysis, the first 4 declarative sentences of the passage were used (total 4 sentences, 134 syllables). Three acoustic dimensions - temporal, spectral, and intensity dimension - with 16 prosodic characteristics were analyzed using Praat software and the ProsodyPro (Xu, Y., 2013). Multivariate Analysis of Covariance (MANCOVA) was used for statistical analysis.
Results: Duration of utterance, pause, and overall pause in the temporal dimension, and jitter (%) in the spectral dimension significantly increased according to the severity of the groups. Also, mean intensity, and maximum intensity significantly decreased when severity increased. However, 4 groups did not show statistical differences in overall speech rate, articulatory speech rate, inappropriate pause, mean f0, minimum f0, maximum f0, f0 variance, minimum intensity, intensity variance, and shimmer.
Conclusions: This study demonstrated the different acoustic characteristics of connected speech according to their dysarthria severity in patients with IPD. The results may contribute to providing clues for exploring the speech biomarker in patients with IPD.
