title: Effect of the ventricular folds in a synthetic larynx model.
abstract: Within the human larynx, the ventricular folds serve primarily as a protecting valve during swallowing. They are located directly above the sound-generating vocal folds. During normal phonation, the ventricular folds are passive structures that are not excited to periodical oscillations. However, the impact of the ventricular folds on the phonation process has not yet been finally clarified. An experimental synthetic human larynx model was used to investigate the effect of the ventricular folds on the phonation process. The model includes self-oscillating vocal fold models and allows the comparison of the pressure distribution at multiple locations in the larynx for configurations with and without ventricular folds. The results indicate that the ventricular folds increase the efficiency of the phonation process by reducing the phonation threshold level of the pressure below the vocal folds. Two effects caused by the ventricular folds could be identified as reasons: (1) a decrease in the mean pressure level in the region between vocal and ventricular folds (ventricles) and (2) an increase in the glottal flow resistance. The reason for the first effect is a reduction of the pressure level in the ventricles due to the jet entrainment and the low static pressure in the glottal jet. The second effect results from an increase in the glottal flow resistance that enhances the aerodynamic energy transfer into the vocal folds. This effect reduces the onset threshold of the pressure difference across the glottis.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany. Electronic address: stefan.kniesburges@uk-erlangen.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kniesburges
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany.
authors.forename: Veronika
authors.initials: V
authors.lastname: Birk
authors.affiliation: Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Germany; Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander Unversity Erlangen-Nürnberg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lodermeyer
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Schützenberger
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Division of Phoniatrics and Pediatric Audiology, University Hospital Erlangen, Medical School at Friedrich-Alexander University Erlangen-Nürnberg, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bohr
authors.affiliation: Department of Process Machinery and Systems Engineering, Friedrich-Alexander University Erlangen-Nürnberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Becker
mesh_terms: D005931:Glottis / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D010699:Phonation; D011312:Pressure; D014827:Vocal Cords / Q000502:physiology*
keywords: Aerodynamics; Fluid-structure interaction; Human phonation; Synthetic larynx model; Ventricular folds