Contribution
Analysis of separated vibration regimes of the vocal folds in a synthetic larynx model
* Presenting author
Abstract:
The fundamental frequency f0 of the human voice is described as interaction between the laryngeal muscles controlling glottal parameters as prestress, length and adduction of the vocal folds, and the airflow. This interplay is difficult to analyze in-vivo. Therefore, the study was performed in an experimental larynx model allowing the independent control of the parameters.The larynx model is made of silicone with characteristic stiffness values comparable to vocal fold tissue in which the adduction and prestress were controlled. During the measurements, the vocal folds were adducted for each combination of prestress and flowrate until stable oscillations occurred.For each combination of flowrate and prestress, the vocal folds started to vibrate at two distinct f0-regimes f0-1 and F02 for two different adduction levels. f0-1 ranged from 160-200 Hz and f0-2 from 250-350 Hz. Furthermore, f0 increased with increasing prestress in the vocal folds. The SPL was higher in f0-2 (69-82 dB) compared to f0-1 (63-75 dB). For constant prestress and flow rate, f0-1 and f0-2 occurred clearly separated. Moreover, the higher SPL in F02 indicates a higher efficiency of the aero-acoustic sound generation at higher f0. This might add to the understanding of vocal registers and related eigenmodes.