The signal origins of glottograms and their relations to vibratory pattern of vocal folds

Signal origins and effect and degree of all factors on photoglottogram (PGG) and electroglottogram (EGG) were analyzed and relations of glottograms to time-phase of vibratory pattern and of vocal cords clarified by computer simulation, in vivo control vibration of canine vocal cords and human phonatory experiments. The results showed that: (1) PGG is linearly related with glottal area; (2) EGG fits the lateral contact area of vocal folds; (3) PGG and EGG characteristics indicate precisely the time-phases of vocal fold vibration. Experimental and clinical data show correctness of the analyzing and processing methods of glottograms by authors.