Faculty Collaboration Database

Onset and offset phonation threshold flow in excised canine larynges. Laryngoscope 2008 Jul;118(7):1313-7

Date

04/11/2008

Pubmed ID

18401267

Pubmed Central ID

PMC3187923

DOI

10.1097/MLG.0b013e31816e2ec7

Scopus ID

2-s2.0-47149098602 (requires institutional sign-in at Scopus site)   26 Citations

Abstract

OBJECTIVES/HYPOTHESIS: In this study, we examined the hypothesis that the minimum flow required for phonation onset, the onset phonation threshold flow (PTF), is greater than the minimum flow to sustain phonation, the offset PTF. We also explored the hypothesis that the ratio of these two (PTF offset divided by PTF onset) falls within [0.707, 1.0].

STUDY DESIGN: This was a methodology study to measure onset and offset PTFs in 10 excised canine larynges; their ratio (PTF offset divided by PTF onset) was predicted to fall in a specific domain.

METHODS: The onset and offset PTF and phonation threshold pressure (PTP) values were observed using 10 excised canine larynges mounted on a bench apparatus. The subglottal flow was increased until phonation was observed, and then decreased until phonation ceased; airflow and pressure measurements at critical conditions of phonation were observed as the PTF and PTP. Larynges with elongated vocal folds were then tested to observe PTF and determine if the hypothesis was observed in pathologic-like larynges.

RESULTS: The offset PTF was always less than the onset PTF (P << .0001) and 80.0% of the observed onset-offset PTF ratios were bound by [0.707, 1.0].

CONCLUSIONS: PTF onset or offset could be a useful diagnostic parameter of the voice, particularly when used in conjunction with PTP to describe laryngeal resistance and aerodynamic power. Further exploration of the relationship between onset and offset PTF values could augment clinical diagnostic ability and advance current theories on the physics of phonation.

Author List

Regner MF, Tao C, Zhuang P, Jiang JJ

Author

Michael Regner MD Associate Professor in the Radiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Air Pressure
Animals
Dogs
Larynx
Models, Theoretical
Phonation
Pulmonary Ventilation
Sensory Thresholds
Vocal Cords