Authors:
Paulo Rogério Scalassara
;
María Eugenia Dajer
;
Carlos Dias Maciel
and
José Carlos Pereira
Affiliation:
School of Engineering of São Carlos, University of São Paulo, Brazil
Keyword(s):
Voice, entropy, phase space reconstruction, nodule, predictability.
Related
Ontology
Subjects/Areas/Topics:
Acoustic Signal Processing
;
Applications and Services
;
Biomedical Engineering
;
Biomedical Signal Processing
;
Computer Vision, Visualization and Computer Graphics
;
Medical Image Detection, Acquisition, Analysis and Processing
Abstract:
Human voice has been a matter of interest for different areas as technological development and medical sciences. In order to understand the dynamic complexity of healthy and pathologic voice, researchers have developed tools and methods for analysis. Recently nonlinear dynamics has shown the possibility to explore the dynamic nature of voice signals from a different point of view. The purpose of this paper is to apply entropy measures and phase space reconstruction technique to characterize healthy and nodule affected voices. Two groups of samples were used, one from healthy individuals and the other from people with nodule in the vocal fold. They are recordings of sustained vowel /a/ from Brazilian Portuguese. The paper shows that nonlinear dynamical methods seem to be a suitable technique for voice signal analysis, due to the chaotic component of the human voice. Since the nodule pathology is characterized by an increase in the signal’s complexity and unpredictability, measures of
entropy are well suited due to its sensibility to uncertainty. The results showed that the nodule group had a higher entropy values. This suggests that these techniques may improve and complement the recent voice analysis methods available for clinicians.
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