The existence of low-frequency modulations in some pathological vocal signals has already been reported by several authors. We have focused on the existence of these non-linear phenomena analysing the vibration of excised animal larynges submitted to asymmetrical situations. This work presents a laser beam device permitting to detect the vibration of each fold both simultaneously and separately. The first data are also proposed.
Index Terms. vocal fold vibration, non-linearities, vocalfold asymmetry