While some aerosol droplets causing airborne transmissions are argued to be produced by vocal fold vibrations, the detailed production mechanisms were unclear due to the difficulty of direct observation. In this study, by using a transparent acrylic vocal fold model and high-speed imaging, we observed vocal fold vibrations that produce droplets of artificial mucus to clarify the relationship between the vocal fold vibration and the droplet production. The vocal fold model was set on a lung model which has a manual diaphragm. The artificial mucus in between the vocal folds was lighted up by a laser sheet. The results showed that droplets were produced when the sound amplitudes were decreased or the fundamental frequency became unstable. We observed that mucus drops attached to the middle of the vocal fold wall splashed and formed a droplet that flew from the vocal fold wall. This suggests that the shear forces of turbulent airflow passing on the mucus mainly produced the droplets.