Real-Time Visual Feedback of Airflow in Voice Training: Aerodynamic Properties of Two Flow Ball Devices.
OBJECTIVE
Flow ball devices have been used as teaching tools to provide visual real-time feedback of airflow during singing. This study aims at exploring static back pressure and ball height as function of flow for two devices, marketed as flow ball and floating ball game.


METHODS
This is a comparative descriptive study.


METHODS
A flow-driven vocal tract simulator was used to investigate the aerodynamic properties of these two devices, testing them for four different ball sizes. The flow range investigated was between 0 and 0.5 L/s. Audio, flow, pressure, and ball height were recorded.


RESULTS
The flow pressure profiles for both tested devices were similar to those observed in previous studies on narrow tubes. For lifting the ball, both devices had a flow and a pressure threshold. The tested floating ball game required considerably higher back pressure for a given flow as compared with the flow ball.


CONCLUSIONS
Both tested devices have similar effects on back pressure as straws of 3.7 and 3.0 mm in diameter for the flow ball and the floating ball game, respectively. One might argue that both devices could be used as tools for practicing semi-occluded vocal tract exercises, with the additional benefit of providing real-time visual feedback of airflow during phonation. The flow threshold, combined with the flow feedback, would increase awareness of flow, rather than of pressure, during exercises using a flow ball device.
Center for Social Sciences, University of Coimbra, Portugal; Institute of Interdisciplinary Research, University of Coimbra, Portugal. Electronic address: filipala@ces.uc.pt.
Filipa M B
FMB
Lã
Faculty of Arts, Psychology and Theology, Abo Akademi University, Turku, Finland.
Greta
G
Wistbacka
Faculty of Culture and Language Sciences, University of St Mark & St John, UK.
Pedro Amarante
PA
Andrade
Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet (KI), Stockholm, Sweden; Basic Science and Biomedicine, School of Technology and Health (STH), Royal Institute of Technology (KTH), Stockholm, Sweden.
Svante
S
Granqvist
D001296:Audiovisual Aids; D004867:Equipment Design; D056228:Feedback, Sensory; D006801:Humans; D009038:Motion; D010699:Phonation; D011312:Pressure; D063346:Singing; D013997:Time Factors; D014741:Video Recording; D014796:Visual Perception; D014833:Voice Quality; D014834:Voice Training
Floating ball game; Flow ball; Real-time visual feedback of airflow; Semi-occluded vocal tract; Voice training