Aerodynamic and acoustic response patterns associated with cheek inflation during straw phonation: An exploratory pilot study

This exploratory pilot study examined preliminary aerodynamic and acoustic response patterns associated with cheek inflation during straw phonation in healthy adults. Eight adults with complete pre–post data were assigned to either a cheek inflation group or a no-cheek-inflation group using a between-subjects design. Aerodynamic variables obtained using the Phonatory Aerodynamic System (PAS) were treated as the primary exploratory outcomes, whereas acoustic measures obtained using real-time pitch (RTP), Multi-Dimensional Voice Program (MDVP), and Analysis of Dysphonia in Speech and Voice (ADSV) were analyzed as secondary exploratory outcomes. Grade, roughness, breathiness, asthenia, strain (GRBAS) ratings were used as a descriptive reference to characterize the auditory-perceptual status of the healthy participants rather than as a primary outcome measure. Given the small sample size, nonparametric analyses and effect sizes were used to describe pre–post changes and between-condition change-score patterns. Pre–post comparisons showed changes in selected PAS variables, including aerodynamic power, peak air pressure, and peak expiratory airflow, while jitter was the only acoustic variable showing a pre–post change. Between-condition comparisons of change scores did not reach statistical significance. However, several PAS variables, particularly phonation time, expiratory airflow duration, and mean expiratory airflow, showed relatively large effect sizes, suggesting possible candidate variables for future investigation. These findings should not be interpreted as evidence of a definitive condition effect, but rather as preliminary observations that may inform future within-subject studies with larger samples and direct physiological measurements.