Evaluating a Vibratory Positive Expiratory Pressure (PEP) Device as a Dysphonia Treatment

Abstract

<h2>Summary</h2><h3>Introduction</h3> Previous work investigating Acapella Choice, a vibratory positive expiratory pressure device, as a form of semi-occluded vocal tract exercise (SOVTE) identified that it promoted large oscillatory pressures and promoted improved vocal economy for normophonic volunteers. Its use in a pathological population has not yet been investigated. <h3>Objectives</h3> To assess the impact of Acapella Choice as an SOVTE in a group of dysphonic patients and compare outcomes to tube-in-water resistance therapy. <h3>Methods</h3> Thirty participants underwent acoustic, electroglottography (EGG) and aerodynamic assessment before and after 3 minutes of phonation with Acapella Choice and with a 9 mm diameter tube in 5 cm of water (WRT). During exercise, aerodynamic and EGG signals were captured simultaneously. Descriptive statistics and tests of significant differences between groups and exercises were carried out. Outcome variables included expert-rated voice quality, sound pressure level, difference in first and second harmonics (H1-H2), cepstral peak prominence, mean contact quotient (CQ), mean peak pressure, mean flow during voicing, laryngeal resistance and aerodynamic power. Participants rated their perceived vocal clarity, strength, and effortlessness as well as vocal tract discomfort utilizing the Vocal Tract Discomfort Scale. <h3>Results and Conclusions</h3> Participants were clustered based on baseline laryngeal resistance, resulting in a high resistance (HR, n = 14) and low resistance (LR, n = 16) groups. Acapella produced twice the static intraoral pressure and oscillatory (root mean square) pressure and flow compared to WRT. Both exercises produced similar static flows. Acapella oscillation frequency was higher than WRT bubbling, but not meaningfully. Flow increased significantly from pre-intervention levels to perform both exercises, and further increased during the task. The glottal response of the groups was categorically different; the HR group had an immediate drop in CQ commencing both tasks, while the LR group demonstrated a steady decline in CQ in Acapella only. Following Acapella, CQ and H1-H2 trended towards normalization. Acapella also produced larger aerodynamic changes. Measures of voice quality deteriorated modestly following both exercises. By contrast, participant ratings of voice production were significantly improved after both tasks, more so with Acapella. The HR group reported significant reductions in tightness and aching following Acapella. Participants favored Acapella, finding it more practical and more likely to be used for daily practice.