Ref: B. Liu, E. Polce, J. C. Sprott, and J. J. Jiang, Journal of
Speech, Language, and Hearing Research 61, 1130-1139 (2018).
Applied Chaos Level Test for Validation of Signal Conditions
Underlying Optimal Performance of Voice Classification Methods
Boquan Liu,a Evan Polce,a
Julien C. Sprott,b and Jack J. Jianga
Department of Surgery-Division of
Otolaryngology, University of Wisconsin School of Medicine and
Public Health, Madison
Department of Physics. University of Wisconsin-Madison
Received June 27, 2017
Revision received November 20, 2017
Accepted January 30, 2018
Purpose: The purpose of this study is to
introduce a chaos level test to evaluate linear and nonlinear
voice type classification method performances under varying
signal chaos conditions without subjective impression.
Study Design: Voice signals were constructed with
differing degrees of noise to model signal chaos. Within each
noise power, 100 Monte Carlo experiments were applied to analyze
the output of jitter, shimmer, correlation dimension, and
spectrum convergence ratio. The computational output of the 4
classifiers was then plotted against signal chaos level to
investigate the performance of these acoustic analysis methods
under varying degrees of signal chaos.
Method: A diffusive behavior detection–based chaos level
test was used to investigate the performances of different voice
classification methods. Voice signals were constructed by
varying the signal-to-noise ratio to establish differing signal
Results: Chaos level increased sigmoidally with
increasing noise power. Jitter and shimmer performed optimally
when the chaos level was less than or equal to 0.01, whereas
correlation dimension was capable of analyzing signals with
chaos levels of less than or equal to 0.0179. Spectrum
convergence ratio demonstrated proficiency in analyzing voice
signals with all chaos levels investigated in this study.
Conclusion: The results of this study corroborate the
performance relationships observed in previous studies and,
therefore, demonstrate the validity of the validation test
method. The presented chaos level validation test could be
broadly utilized to evaluate acoustic analysis methods and
establish the most appropriate methodology for objective voice
analysis in clinical practice.
The complete paper is available in PDF
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