Document Detail


Effects of low-pass filtering on acoustic analysis of voice.
MedLine Citation:
PMID:  20346621     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE/HYPOTHESIS: Low-pass filtering is often applied to eliminate effects of environmental noise when preparing voice recordings for acoustic analysis. This study tested the effects of low-pass filter cutoff frequency on the results of acoustic voice analysis, with a particular interest in the effects of low cutoff frequencies on nonlinear dynamic parameters.
STUDY DESIGN: A crossover randomized controlled trial was performed using voice recordings of sustained vowel phonation obtained from the Disordered Voice Database.
METHODS: A second-order Butterworth filter was applied to the voices at cutoff frequencies ranging from 5000 to 40 Hz. Percent jitter, percent shimmer, fundamental frequency (F(0)), signal-to-noise ratio (SNR), correlation dimension (D(2)), and second-order entropy (K(2)) were calculated for each signal.
RESULTS: Traditional acoustic parameters were validly measured at cutoff frequencies as low as 300 Hz. The SNR and percent shimmer were improved by cutoff frequencies of 300 Hz or higher; F(0) and percent jitter were unaffected by filtering at these frequencies. D(2) and K(2) were measured stably for signals filtered at cutoff frequencies as low as 100 Hz.
CONCLUSION: To ensure accuracy in acoustic voice analysis, setting the cutoff frequency of a low-pass filter at least one octave above the F(0) (minimum of 300 Hz) is recommended. Nonlinear dynamic measures of D(2) and K(2) proved more robust and maintained accuracy at lower frequencies.
Authors:
Julia K MacCallum; Aleksandra E Olszewski; Yu Zhang; Jack J Jiang
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural     Date:  2010-03-25
Journal Detail:
Title:  Journal of voice : official journal of the Voice Foundation     Volume:  25     ISSN:  1557-8658     ISO Abbreviation:  J Voice     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2011-01-10     Completed Date:  2011-04-22     Revised Date:  2012-01-04    
Medline Journal Info:
Nlm Unique ID:  8712262     Medline TA:  J Voice     Country:  United States    
Other Details:
Languages:  eng     Pagination:  15-20     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 The Voice Foundation. Published by Mosby, Inc. All rights reserved.
Affiliation:
Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, Medical Sciences Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706-1532, USA.
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MeSH Terms
Descriptor/Qualifier:
Adult
Artifacts
Cross-Over Studies
Female
Humans
Male
Middle Aged
Nonlinear Dynamics
Phonation*
Reproducibility of Results
Signal Processing, Computer-Assisted*
Speech Acoustics*
Speech Production Measurement*
Time Factors
Voice*
Young Adult
Grant Support
ID/Acronym/Agency:
1-R01DC05522-01/DC/NIDCD NIH HHS; R01 DC005522-01/DC/NIDCD NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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