A Comparison of the Effects of Phonation into a Positive Expiratory Pressure Device and Silicone Tube in Water on the Vocal Mechanism.

Objectives: Positive expiratory pressure (PEP) devices have become an additional therapeutic approach for treating voice disorders. Similar to water resistance therapy (WRT), phonation in a PEP device introduces a secondary source of vibration within the vocal tract. This investigation aimed to compare the effects of phonation using a PEP device and silicone tube phonation (STP) commonly used in WRT on the vocal mechanism during phonation.

Methods: Three normophonic subjects participated in the study. High-speed videoendoscopy, pressure, airflow, electroglottography, and acoustic recordings were collected.

Results: The results demonstrated that phonation using both the PEP device and silicone tube induced alterations in glottal behavior. The PEP device produced more pronounced and consistent pressure oscillations, impacting the glottal cycle and influencing parameters including contact quotient (CQ), fundamental frequency, glottal area, pressure, and airflow. The regular vibratory mechanism of the PEP device systematically modified the glottal cycle. In STP, regular bubbling at lower depths of submersion produced higher CQ values, supporting the efficacy of deep bubbling exercises for inducing glottal adduction.

Conclusions: The findings suggest that phonation using PEP devices has a more pronounced impact on the vocal tract and glottis. It also provides a stronger massage effect that directly affects the glottal source. Phonation with a silicone tube produces similar results, although to a lesser extent and with lower regularity. These findings offer guidance in the selection of voice therapy devices.