Calibration of external lighting and sensing photoglottograph

Anne Bouvet (1) , Annemie van Hirtum (1) , Xavier Pelorson (1) , Shinji Maeda (2) , Kiyoshi Honda (2) , Angelique Amelot (2)

1 GIPSA-GAMA - GIPSA - Group aeroacoustics, modeling and application
2 LPP - LPP - Laboratoire de Phonétique et Phonologie - UMR 7018

Observation and measurement of vocal folds vibration and glottal opening during speech requires techniques as little invasive as possible for the subject. The LPP has developed the External Photoglottograph (ePGG) system. It consists of illuminating the glottis through the neck skin with an infrared light and recording light variation intensity modulated by glottal movement with a photodiode placed across the larynx. The system is tested on two mechanical larynx replicas. The first one consists of two rigid half cylinders in forced oscillation controlled by a step motor. The second one is flow driven and uses latex tubes filled with water in order to reproduce vocal folds self-oscillation. Time-varying glottal area is measured accurately for both replicas. Experimental results are compared to ePGG recordings in order to assess the correlation between area measurements and ePGG signal. This characterization is used to propose a calibration of the glottal opening as a function of parameters affecting the ePGG signal (distance, angle, skin, tissue, system setting, etc.).

Mots clés: ePGG; glottal area; vocal folds auto-; oscillation; non-invasive measurement; mechanical; replica

Domaines: Optique / photonique; Biomécanique [physics.med-ph]

Anne Bouvet, Annemie van Hirtum, Xavier Pelorson, Shinji Maeda, Kiyoshi Honda, et al.. Calibration of external lighting and sensing photoglottograph. MAVEBA 2017 - 10th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, Dec 2017, Florence, Italy. ⟨hal-01671688⟩