Vibratory pattern analysis of vocal folds for layngeal function assessment usig electroglottograph system

In this study, we have evaluated the effect of amplitude and frequency perturbation of EGG signal during single vowels associated with laryngeal pathology. The normal EGG signal is properly characterized by an autoregressive model which has the optimal order of ninth using the parametric method. This can be analyzed by determining the transfer function. Perturbations in the fundamental pitch and in the peak amplitude of EGG signal derived with a four-electrode system using the modulation/demodulation techniques were investigated for the purpose of developing a decision criteria for the laryngeal function identification.