Evaluation of excised porcine larynx frequency changes due to changing vocal fold elastic properties

Abstract

The work presented in this study investigates the impact of changing vocal fold elastic properties on the frequencies of vibration during phonation. Excised porcine larynx tests were conducted to examine the relationship between porcine vocal fold anterior-posterior strain and the resulting changes in the phonation frequency. During each test, two high speed cameras (4000 FPS) and a microphone (44100 Hz) were used to record changes in vocal fold dynamics while a servo motor stretched the tissue in the anterior-posterior direction. A digital image correlation tracking method was then used to measure anterior-posterior strain on the exposed porcine vocal fold superior surface. Strain measurements were related to changes in vocal fold elasticity based on previously reported mean elastic parameters which describe porcine vocal fold elasticity from 0%–40%. Additionally, an aeroelastic model of phonation which incorporates the measured vocal fold geometry, elastic properties, and air flow characteristics was implemented to further study the impact of changing porcine vocal fold elasticity on the vibration frequency. Phonation was first observed at a strain of 0.18 mm/mm with a fundamental frequency of 246 Hz and increased to 404 Hz at a strain of 0.35 mm/mm. Airflow conditions were kept constant during all experimental tests.The work presented in this study investigates the impact of changing vocal fold elastic properties on the frequencies of vibration during phonation. Excised porcine larynx tests were conducted to examine the relationship between porcine vocal fold anterior-posterior strain and the resulting changes in the phonation frequency. During each test, two high speed cameras (4000 FPS) and a microphone (44100 Hz) were used to record changes in vocal fold dynamics while a servo motor stretched the tissue in the anterior-posterior direction. A digital image correlation tracking method was then used to measure anterior-posterior strain on the exposed porcine vocal fold superior surface. Strain measurements were related to changes in vocal fold elasticity based on previously reported mean elastic parameters which describe porcine vocal fold elasticity from 0%–40%. Additionally, an aeroelastic model of phonation which incorporates the measured vocal fold geometry, elastic properties, and air flow characteristics was im...