Document Detail


Acoustic impedance of an artificially lengthened and constricted vocal tract.
MedLine Citation:
PMID:  11130104     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Voice training techniques often make use of exercises involving partial occlusion of the vocal tract, typically at the anterior part of the oral cavity or at the lips. In this study two techniques are investigated: a bilabial fricative and a small diameter hard-walled tube placed between the lips. Because the input acoustic impedance of the vocal tract is known to affect both the shaping of the glottal flow pulse and the vibrational pattern of the vocal folds, a study of the input impedance is an essential step in understanding the benefits of these two techniques. The input acoustic impedance of the vocal tract was investigated theoretically for cases of a vowel, bilabial occlusion (fully closed lips), a bilabial fricative, and artificially lengthening the tract with small diameter tubes. The results indicate that the tubes increase the input impedance in the range of the fundamental frequency of phonation by lowering the first formant frequency to nearly that of the bilabial occlusion (the lower bound on the first formant) while still allowing a continuous airflow. The bilabial fricative also has the effect of lowering the first formant frequency and increasing the low-frequency impedance, but not as effectively as the extension tubes.
Authors:
B H Story; A M Laukkanen; I R Titze
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of voice : official journal of the Voice Foundation     Volume:  14     ISSN:  0892-1997     ISO Abbreviation:  J Voice     Publication Date:  2000 Dec 
Date Detail:
Created Date:  2000-12-20     Completed Date:  2001-03-01     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8712262     Medline TA:  J Voice     Country:  United States    
Other Details:
Languages:  eng     Pagination:  455-69     Citation Subset:  IM    
Affiliation:
National Center for Voice and Speech, Wilbur James Gould Voice Research Center, Denver Center for the Performing Arts, Colorado, USA.
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MeSH Terms
Descriptor/Qualifier:
Acoustic Impedance Tests*
Humans
Models, Biological
Phonation / physiology*
Phonetics
Voice / physiology*
Grant Support
ID/Acronym/Agency:
P60-DC00976/DC/NIDCD NIH HHS

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


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