No abstract

Articulatory rate and pause time in a standardized reading task in Parkinson's disease (PD) patients in correlation to disease duration and severity as compared to healthy controls were analyzed. In 121 PD patients and 70 healthy controls, an acoustical analysis was performed on the first and last sentence of a standardized 170-syllabic text, using a commercial audio software. Articulatory rate and speech to pause ratios were calculated by measuring the length of each syllable and each pause both at the end of words and within polysyllabic words. No significant difference in overall articulatory rate was found between PD patients and controls. Both groups showed an accelerated speech rate in the last sentence compared to the first; however, PD patients had a higher speech acceleration than did controls. PD patients exhibited a significantly reduced percental pause duration in relation to total speech time in the first sentence and a reduced percental pause time within polysyllabic words. PD patients made significantly less but longer pauses at the end of words and less pauses within polysyllabic words. UPDRS III showed an inverse relation to number and rate of intraword pauses, and disease duration was negatively correlated with articulatory rate. The characteristics of parkinsonian speech feature was not only a stronger acceleration of articulation rate in the course of speaking but also a significant reduction of the total numbers of pauses, indicating an impaired speech rhythm and timing organization.

Parkinsonian speech or hypokinetic dysarthria results from a multidimensional impairment of phonation, articulation, and prosody. Although the dysprosody in Parkinson's disease (PD) is well described (alterations in speech rate and pause time, speech intensity and pitch variation), little is known about alterations of these single prosodic parameters over a longer time course. The objective of this study is to analyze changes of speech rate and pitch variation in patients with PD over time and to compare these findings with healthy controls. Patients with PD (N = 50; 27 male and 23 female) and n = 50 age-matched healthy controls (25 male, 25 female) were tested and retested after at least 7 months (mean: 25.02; median: 21; SD: 17.44; range: 7-79 months). In the PD group, motor impairment according to UPDRS motor score was similar at first and second visit. The participants had to accomplish a standardized four sentence reading task. The acoustical analysis was performed using a standard head-worn microphone for voice recordings and commercial audio software (WaveLab). For the determination of intonation based upon fundamental frequency (F(0)) variation, we used a computer analysis program (Praat). Articulatory velocity was determined by measurement of syllable rate and pause ratios. In the PD group, total speech rate (syllables per second related to total speech time/TSR) and net speech rate declined from first to second examination, especially in the male patients, but showed no significant differences to the control group. The course of pitch variation revealed some gender particularities. Whereas female patients' pitch variability declined over time, male patients' intonation variability remained relatively stable. F(0) variation in male and female patients with PD were significantly reduced compared with the control group in the first examination and the follow up as well. Progression of prosodic impairment over time showed no correlation to disease duration or UPDRS motor score. Some aspects of dysprosody in PD show characteristic changes over time, but show no clear correlation with general motor impairment as assessed by UPDRS motor score. Therefore, we suspect that the underlying mechanism could be independent from dopaminergic deficits.

While the beneficial effect of levodopa on motor impairment in Parkinson's disease (PD) has been well documented, its effect on speech has rarely been examined and the respective literature is inconclusive. The aim of our study was to analyze the effect of short-term levodopa admission and long-term dopaminergic treatment on speech in PD patients in early stages of the disease. Motor examination according to UPDRS III and speech testing were performed in 23 PD patients (9 males; median age 68, 42-78 years) in the early morning after having abstained from dopaminergic medication overnight ("off" state, t0) after administration of 200 mg of soluble levodopa (t1), and at follow-up after 12-14 weeks under stable dopaminergic medication (t2). Speech examination comprised the perceptual rating of global speech performance and an acoustical analysis based upon a standardized reading task. While UPDRS III showed a significant amelioration after L: -dopa application, none of the parameters of phonation, intonation, articulation and speech velocity improved significantly in the "on" state, neither under short-term levodopa administration (t1) nor on stable dopaminergic treatment (t2). However, there was a positive effect of dopaminergic stimulation on vowel articulation in individual patients. Results indicated significant beneficial effect of short-term levodopa administration or long-term dopaminergic medication on different dimensions of speech in PD patients. As some improvement of vowel articulation was seen in individual patients, the pre-existing pattern of speech impairment might be responsible for the different response to pharmacological treatment.

The aim of this study is the analysis of continuous speech signals of people with Parkinson's disease (PD) considering recordings in different languages (Spanish, German, and Czech). A method for the characterization of the speech signals, based on the automatic segmentation of utterances into voiced and unvoiced frames, is addressed here. The energy content of the unvoiced sounds is modeled using 12 Mel-frequency cepstral coefficients and 25 bands scaled according to the Bark scale. Four speech tasks comprising isolated words, rapid repetition of the syllables /pa/-/ta/-/ka/, sentences, and read texts are evaluated. The method proves to be more accurate than classical approaches in the automatic classification of speech of people with PD and healthy controls. The accuracies range from 85% to 99% depending on the language and the speech task. Cross-language experiments are also performed confirming the robustness and generalization capability of the method, with accuracies ranging from 60% to 99%. This work comprises a step forward for the development of computer aided tools for the automatic assessment of dysarthric speech signals in multiple languages.