Real-Time Visual Feedback of Airflow in Voice Training: Aerodynamic Properties of Two Flow Ball Devices

Abstract

Objectives: 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. Study design: Comparative descriptive study. Method: 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. Conclusion: Both tested devices have similar effects on back pressure as straws of 3.7 and 3.0 mm 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.

Augmented visual-feedback of airflow: Immediate effects on voice-source characteristics of students of singing

“…In 2014, co-author F.M.B.L. introduced the use of the flow ball (FB, see Figure 3) as a novel real-time visual feedback of phonatory airflow for voice training (Lã et al, 2017); the user phonates into a narrow tube ending in a basket with a polystyrene ball in it. The phonatory airflow lifts the ball to a height that varies in proportion to the airflow.…”

“…The phonatory airflow lifts the ball to a height that varies in proportion to the airflow. For example, an airflow of 0.3 L/s is reflected as a ball height of 5 cm (Lã et al, 2017). Hence, phonation with different adjustments of glottal adduction, at different fundamental frequencies ( f o ) and degrees of vocal loudness, P sub , is visualized in terms of ball height.…”

“…Phonating Into a Flow Ball Offering Real-Time Visual Feedback of Phonatory Airflow in Terms of Ball Height. In the Photograph, the Ball Reaches Approximately 7 cm Height, Which Corresponds Approximately to an Airflow of Approximately 0.4 L/s (Lã et al, 2017). …”

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“…De asemenea, Flow-Ball se poate utiliza și pentru creșterea volumului respirator, a tonifierii musculare implicate în actul respirator, dar și pentru a relaxa și tensiona musculatura implicată în actul fono-articulator. Lã, Wistbacka, Andrade, Granqvist (2017) au subliniat valoare acestui tip de instrumente în educarea respirației cu scopul modelării vocii, subliniind că biofeedback-ul vizual care este asigurat de urmărirea mingii ce trebui să fie propulsată în aer, alături de antrenarea respirației prin tub (Smith, Titze, 2017), conduce la îmbunătățirea clară a capacității de expir, iar abilitatea de prelungire a expirului este absolut necesară în actul fonator.…”

A Pilot Study Assessing the Therapeutic Potential of a Vibratory Positive Expiratory Pressure Device (Acapella Choice) in the Treatment of Voice Disorders

“…Those engaged in voice rehabilitation are no exception; devices which have been found to have clinical application in dysphonia but which were developed for a different purpose include kazoos 1 , 'flow ball' toys 2 and variably occluded face masks 3,4 .…”