How Acoustic Resonances Can Support Self-sustained Oscillations of Acoustic-Mechanical Dynamic System

0538751 - ÚT 2021 RIV SG eng C - Conference Paper (international conference)
Horáček, Jaromír - Radolf, Vojtěch - Laukkanen, A. M.
How Acoustic Resonances Can Support Self-sustained Oscillations of Acoustic-Mechanical Dynamic System.
Proceedings of the 14th International conference on vibration problems. ICOVP 2019. Singapur: Springer, 2020, s. 389-399. Lecture Notes in Mechanical Engineering. ISBN 978-981-15-8048-2. ISSN 2195-4356. E-ISSN 2195-4364.
[International conference on vibration problems. ICOVP 2019 /14./. Hersonissos (GR), 01.09.2019-04.09.2019]
R&D Projects: GA ČR(CZ) GA19-04477S
Institutional support: RVO:61388998
Keywords : acoustic-flow-structure interaction * biomechanics of voice * vocal tract acoustics * phonation into tubes * water resistance voice therapy * water bubbling frequency * formant frequencies
OECD category: Acoustics

Flutter instabilities of structures aremostly unwanted phenomena in technical applications excluding some energy harvesting systems that utilize wind or water flow-induced aeroelastic instabilities of the systems. Another situation is in biomechanics of voice where the flutter instability of human vocal folds is a necessary condition for singing and speaking, because flow-induced vibrations of the vocal folds create the voice source. The present experimental modelling study shows that the vocal fold self-oscillations can be strongly influenced by interaction with acoustic resonances of the human vocal tract in case when the vocal tract is prolonged by so-called resonance tube used in voice therapy methods. This influence is demonstrated by constructing the relationships of subglottal pressure (pressure drop between trachea and ambient air in front of the mouth) variation in time versus glottal area variation (opening and closing of the glottis). It is shown that a part of the airflow energy required for phonation is substituted by acoustic energy, utilizing the first acoustic resonance.
Permanent Link: http://hdl.handle.net/11104/0316981