Phonation threshold power in ex vivo laryngeal models

摘要

This study hypothesized that phonation threshold power is measureable and sensitive to changes in the biomechanical properties of the vocal folds. Phonation threshold power was measured in three sample populations of ten excised canine larynges treated with variable posterior glottal gap, variable bilateral vocal fold elongation, and variable vocal fold lesioning. Posterior glottal gap was varied from 0 mm to 4 mm in 0.5 mm intervals. Bilateral vocal fold elongation was varied from 0% to 20% in 5% intervals. Vocal fold lesion treatments included unilateral and bilateral vocal fold lesion groups. Each treatment was investigated independently in a sample population of ten excised canine larynges. Linear regression analysis indicated that phonation threshold power was sensitive to posterior glottal gap (R²=0.298, p<0.001) and weakly to vocal fold elongation (R²=0.052, p=0.003). A one-way repeated measures ANOVA indicated that phonation threshold power was sensitive to the presence of lesions (p<0.001). Theoretical and experimental evidence presented here suggests that phonation threshold power could be used as a broad screening parameter, sensitive to certain changes in the biomechanical properties of the larynx. It has not yet been measured in humans, but because it has the potential to represent the airflow-tissue energy transfer more completely the phonation threshold pressure or flow alone, it may be a more useful parameter than these and could be used to indicate that laryngeal health is likely abnormal.