Acoustic analyses of sustained and running voices from patients with laryngeal pathologies.

In this paper, we investigated the acoustic characteristics of sustained and running vowels from normal subjects and patients with laryngeal pathologies. Perturbation methods (including jitter and shimmer), signal-to-noise ratio (SNR), and nonlinear dynamic methods (such as correlation dimension and second-order entropy) were used to analyze sustained and running vowels. We found that the sustained vowels and running voices from normal subjects and patients with laryngeal pathologies had low-dimensional dynamic characteristics. For sustained vowels, the analyses of jitter, shimmer, correlation dimension, and second-order entropy revealed significant differences between normal and pathological voices. For running voices, jitter and shimmer did not statistically discriminate between normal and pathological voices, but a significant difference was found for SNR, correlation dimension, and second-order entropy. The results suggest that nonlinear dynamic analysis and traditional SNR analysis may be valuable for the analysis of sustained and running vowels; perturbation analysis may be applicable for the analysis of sustained vowels but should be applied with caution for running voice analysis.