Abstract
The electroglottogram (EGG) has been used to obtain details of vocal fold vibration. However, applications of EGG are limited in use for voice disorders in speech clinics. The reason being that characteristics of EGG wave form associated with vocal fold vibrations are still poorly understood.
Therefore, we analyzed the EGG waveform characteristics to compare with simultaneous measurement of the supra and subglottic pressure in the normal male subject to sustain the vowel/a/ at comfortable pitch and intensity levels.
In this study, the periodicities of the consequent frequency are completely coincident between the EGG, supra and subglottic pressure weveforms. Regarding the variations of EGG waveform of the vibratory cycles of the vocal folds, increasing phase of EGG wave showed the rapid increase to the subglottic pressure maximum and the decrease of the supra glottic pressure indicating the closing phase of the vocal folds. The gradual subsidence of EGG waveform associated with the parting of the vocal folds demonstrated the increasing of supraglottic pressure from the lowest values and the constacny of lower subglottic pressure.
The negative flatter portion of the EGG wave corresponding to the opened phase showed the higher positive supraglottal pressure and the lower pressure of the subglottic.
Simultaneous comparison of EGG waveform Supra and subglottic pressure measurements might provide useful and detailed information for understanding the EGG wave forms.
