This thesis examined the effects of combination inhaled corticosteroids (ICs) on the stability of six aerodynamic measures of phonation utilizing a traditional benchtop model with leporine larynges. The motivation for this study was based on the increase of voice disorders associated with IC use in recent years. The aerodynamic measures examined were phonation threshold pressure (PTP), phonation threshold flow (PTF), onset resistance, sustained pressure, sustained flow, and sustained resistance. Leporine larynges were selected as the model for this study due to histological similarities between leporine and human vocal folds that make them ideal for translational research. Rabbits were either exposed to saline solution or ICs for 8 weeks before being sacrificed. After being sacrificed, larynges were excised and dissected. After dissection, the larynges were mounted on a benchtop, the aerodynamic data were gathered, and stability over multiple phonation trials was calculated. The results indicate that the variation between individual rabbits across the measures did not differ significantly. However, after controlling for trial, the average variation of the groups across all trials did differ significantly. PTP and sustained pressure were more variable for the inhaler group, while PTF, sustained flow, onset resistance, and sustained resistance were more variable for the control group. These results suggest that some level of variability in aerodynamic measures both within and between subjects is to be expected when using the leporine benchtop model. Furthermore, while IC exposure does not seem to impact within-subject variability, it does influence between-subjects variability.



College and Department

David O. McKay School of Education



Date Submitted


Document Type





phonation pressure, phonation flow, laryngeal resistance, excised larynx, benchtop model



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