Mechanism of Vocal Phonation in T-E Shunt Patients after Total Laryngectomy / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Total laryngectomy has become a usual treatment for any advanced carcinoma of the larynx, but most patients who have undergone total laryngectomy have shown permanent disability in voice production. To solve this problem, studies of voice rehabilitation after total laryngectomy have been done. MATERIALS AND METHODS: We have developed an accurate method to measure the vocal tract shape along its length from magnetic resonance images acquired during the sustained phonation of Korean vowels by T-E shunt patients and normal subject. We estimated the accuracy of MRI and also compared the vocal tract spape of the normal and T-E shunt patients by comparing the first three formant frequencies estimated from MRI to those measured directly from speech data of the T-E patients and the normal subject. RESULTS: The length of T-E shunt patient's vocal tract is 17-18.5 cm. T-E shunt patients phonated strained voice. The length of resonant chamber of T-E shunt patients are shorter than that of the normal subject. The vocal tract is shortened during the phonation by T-E shunt patients. In cases of /e/ and /i/, front cavities are constricted while back cavities are shortened. The pseudoglottis of the T-E shunt patients is located at the region 14-15 cm from lip. CONCLUSION: Acoustic characteristics and vocal tract shapes of the T-E shunt patients are relatively similar to those of the normal subject. To achieve normal voice, reconstruction of pharyngeal and superior glottal resonant chamber will be desirable.