Modelling of Human Vocal Folds and Systematic Investigation of their Vibrations from Kymogram

The systematic investigation of the vocal folds’ physical phenomenon and corresponding kymographic vibratory patterns can establish clinically important relationships which are vital in the diagnosis of laryngeal disorders. The routine investigation is often done clinically through the in-vivo examination of human vocal folds using laryngoscopes. Physical modelling of human vocal folds overcomes the accessibility limitations of the laryngoscopes in imaging the medial and coronal parts of the vocal folds in-vivo, thus allowing investigation of mucosal wave propagation for different geometrical configurations of the vocal folds. Here, the modelled vocal folds are fabricated using flexible silicone compounds, which can closely reproduce the vibratory characteristics of human vocal folds. The kymogram, generated by recording the vibration pattern of the vocal folds, is useful in the analysis of its functional characteristics. The systematic investigation involves quantification of the vibratory parameters from the kymogram of the modelled vocal folds and establishing its relationship with the physical phenomenon. From the quantification, the important parameters: amplitude, open quotient, closed quotient, speed quotient and skewness are analysed. The quantified parameters reflect the influence of physical parameters on the vibratory characteristics of the vocal folds.