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Updated: Jun 2, 2026
09:58
Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp
Published on: February 3, 2014
Phonation instability flow in excised canine larynges
Matthew R Hoffman1, Adam L Rieves, Adam J Budde
1Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
Summary
Phonation instability flow (PIF) and phonation flow range (PFR) effectively measure vocal fold vibration changes due to glottal gaps. These aerodynamic parameters offer valuable insights for voice disorder assessment.
Area of Science:
- Laryngology and Voice Science
- Aerodynamics of Phonation
- Biomechanical Analysis of Voice Production
Background:
- Voice disorders often involve abnormal subglottal pressure and airflow.
- Phonation instability pressure (PIP) has been used to assess chaotic phonation onset.
- New aerodynamic parameters are needed to quantify phonation stability.
Purpose of the Study:
- To introduce and measure phonation instability flow (PIF), the airflow at which phonation becomes chaotic.
- To propose phonation flow range (PFR) as the difference between PIF and phonation threshold flow (PTF).
- To evaluate the dependence of PIF and PFR on laryngeal elongation and glottal gap size.
Main Methods:
- Utilized seven ex vivo canine larynges in a repeated measures design.
- Measured pressure and airflow at phonation and chaos onset under varying elongation and glottal gap conditions.
- Employed paired t tests to analyze differences in aerodynamic parameters.
Main Results:
- Both PIF and PFR were significantly influenced by the presence of a glottal gap (abduction), but not by laryngeal elongation.
- PIF and PFR demonstrated greater sensitivity to abduction than phonation threshold pressure (PTP) or PTF.
- PIP showed no significant dependence on elongation or abduction.
Conclusions:
- PIF and PFR are potentially valuable aerodynamic parameters for voice analysis.
- These measures may be particularly useful in evaluating voice disorders associated with glottal gaps, such as vocal fold paralysis.
- The findings suggest PIF and PFR can aid in experimental and clinical voice assessments.
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