1996 Fiscal Year Final Research Report Summary
| Project/Area Number |
07671862
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Ehime University |
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Principal Investigator |
YUMOTO Eiji Ehime University, School of Medicine, Assistant Professor, 医学部・付属病院, 講師 (40116992)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Hidemitsu Ehime University, School of Medicine, Research Associate, 医学部, 助手 (30187223)
MORI Toshihiro Ehime University, School of Medicine, Research Associate, 医学部, 助手 (50200374)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Vocal fold vibration / Phonation / Mucosal wave / Wave velocity・amplitude / airflow / Vocal fold tension / Fundamental frequency |
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| Research Abstract |
Vertical and horizontal movements of the vocal fold was simultaneouly recorded under two conditions : increase in airflow and longitudinal tension of the vocal fold. Four canine excised larynges were used.
Velocity and amplitude of vocal fold vibration in the vertical direction became maximal at the mid portion of the membranous vocal fold. Under a given tension, vertical velocity and amplitude increased as airflow was increased. Lengthening of the vocal fold resulted in a decrease in vertical velocity and amplitude in three of the four larynges. The other showed an increase in vertical velocity and amplitude, which decreased as the vocal fold tension was increased further. Lengthening of the vocal fold invariably caaused an increase in fundamental frequency (F_0).
The vocal fold moved up during a closed phase of a vibration. An upward velocity showed a maximum at the initial period of the opening phase and decreased subsequently. At the middle of the opening phase, the vertical velocity turned downward. The vocal fold moved downward when the glottis was maximal. The downward velocity became maximal at the middle of the closing phase. The vertical movement again became upward at the later period of the closing phase. Then, the upward velocity increrased, followed by the closure of the glottis.
An increase in airflow resulted in an increase in F_0. However, the relations of the vertical velocity with F_0 in the given larynx were different between the conditions with and without lengthening of the vocal fold.
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