Objective: To discuss the influence of changes in vocal cords' cover-body on their vibratory pattern.
Methods: Fifty adult patients with vocal polyps were observed by telescopic videolaryngostroboscopy and detected by electroglottography (EGG). We examined the vocal cords' vibratory pattern according to laryngostroboscopic image and discussed the change of vocal cords' vibratory parameters and EGG curves.
Results: The vocal cords' vibratory parameters and EGG curves changed with different vocal polyps. All vocal polyps affect the regularity(REG), amplitude (AMP), glottal closure(GLO) and mucosal wave(MUC) of laryngostroboscopic image; the symmetry(SYM), REG and GLO bore linear correlation to the notches in EGG curves, the REG and MUC bore linear correlation to the steep changes; micro-polyps with pedicles reduced the vibratory parameters CQ and F0, the main abnormalities were notches in EGG curves; the changes in macro-polyps with pedicles were the same as the micropolyps except increased CQ. All vocal polyps with wide bases either single or bilateral, had increased CQ and F0, the main abnormalities were steep in contact opening phase and flat in wave peak.
Conclusions: Studies with laryngostroboscopy and EGG revealed how the vocal polyps affected vocal cords' cover-body, changed the vibratory pattern of vocal cords, and factors regulating vocal cords' vibratory pattern.