Objective Parkinson's disease (PD) is a progressive neurodegenerative disorder in which early diagnosis remains difficult due to subtle and heterogeneous symptoms. Speech impairments, particularly hypokinetic dysarthria, often appear early and offer promise as non-invasive biomarkers for detection. This study investigates whether quantitative speech-derived acoustic features can serve as reliable, non-invasive biomarkers for early detection of PD by analysing dysphonia measures extracted from sustained phonation recordings. Method A two-pronged analytical framework was used. First, exploratory data analysis was performed on 16 dysphonia features from 5875 sustained phonation samples collected from 42 individuals with idiopathic PD to examine feature distributions, correlations, and redundancies. Second, principal component analysis was applied to address multicollinearity among vocal features, and the resulting components were used as predictors in multiple regression-based machine learning models. Ensemble, kernel-based, and linear models were compared using standard metrics. Result Ensemble models delivered the strongest predictive performance. Random forest explained 91% of variance ( R 2 = 0.910 for motor Unified Parkinson's Disease Rating Scale (UPDRS); 0.901 for total UPDRS), with root mean squared error (RMSE) = 2.39 and 8.33 and mean absolute error (MAE) = 1.85 and 6.95, respectively. Gradient boosting explained 90% of variance ( R 2 = 0.900 for motor and total UPDRS), with RMSE = 2.52 and 8.42, and MAE = 1.86 and 7.14. Linear models performed substantially worse, consistently yielding R 2 < 0.12, indicating limited ability to capture nonlinear patterns in dysphonia characteristics. Conclusion Speech-derived acoustic biomarkers, when paired with machine learning, especially ensemble methods, show strong potential for accurate, scalable, and cost-effective assessment of PD severity. These findings highlight the potential of speech-derived acoustic biomarkers, coupled with machine learning, as scalable, cost-effective, and objective tools for improving diagnostic precision and enabling earlier intervention in PD.
Chauhan et al. (Sun,) studied this question.