Effects of Humidification of the Vocal Tract and Respiratory Muscle Training in Women With Voice Symptoms—A Pilot Study

Abstract

The aim of this study was to determine the efficacy of a 4-week breathing exercise intervention in participants with voice symptoms. Six nonsmoking women (mean age 49) experiencing voice symptoms used a novel device WellO2 for respiratory exercises that provides counter pressure during both inspiration and expiration and warms and humidifies the breathing air. Speech samples were acoustically (Acoustic Voice Quality Index) and perceptually (grade, roughness, breathiness, asthenia, and strain scale) analyzed, and perceived voice symptoms and self-reported effort in breathing and phonation were obtained. Respiratory measurements included breathing frequency and pattern, peak expiratory flow, forced vital capacity, and forced expiratory volume in 1 minute. The total scores of Acoustic Voice Quality Index and some of its subcomponents (shimmer and harmonic-to-noise ratio), and the grade, roughness, and strain of the GRBAS scale indicated significantly improved voice quality. However, neither the nature or frequency of the experienced voice symptoms nor the perceived phonatory effort changed as the function of intervention. According to the participants, their breathing was significantly less effortful after the intervention, although no significant changes were observed in the objective respiratory measurements with a spirometer. Training with the WellO2 device has the potential to improve voice quality. The combination of inspiratory and expiratory training and warmed, humidified air is a multifaceted entity influencing several parts in the physiology of voice production. The effects of using WellO2 need to be confirmed by further studies with a larger number of participants.