목적: To investigate the acoustic characteristics of 'wet voice' that occurs when liquid penetrates the vocal fold. 방법:A videofluoroscopic swallowing study was performed on patients diagnosed with thyroid cancer before operation. The subjects of this study were 7 patients whose vocal fold was touched by liquid contrast medium. The control group included 7 patients with thyroid cancer. As an examination procedure, the subjects were asked to phonate the vowel /e/ without eating, and then to drink more than 10 cc of contract medium, and to phonate /e/ again, and both the videofluoroscopic image and voice were recorded. As variables, the first formant bandwidth (B1), as well as the amplitude of the first, second and fourth harmonics (H1, H2, H4) were measured. In addition, the maximum amplitude in the first, second and third formant (A1, A2, A3) and the amplitude in high frequency (2K, 5K) were measured. Further, the variables related to the slope of high spectrum (H1-H2, H1-A1, H1-A2, H1-A3, H2-H4, 2K-5K) were measured. In addition, CPP, Energy, HNR, SHR and F0, which are associated with voice disorder, were measured. 결과:In the whole vowel section, the effect size was statistically significant in the descending order of B1, H1-A1, H1-H1 (*) and H1-A2 (p<.05). In the beginning section of vowel, the effect size was statistically significant in the order of H1-A1 (*), H1-A1, B1, H1-A2 (*), A1 (*), A2 (*), HNR (0-1500Hz) and A1 (p<.05). In the middle of vowel, the effect size was statistically significant in the order of H1-A1 (*), H1-A1, 2K (*)-5K and A1 (p<.05) 결론:The acoustic variables for identifying the occurrence of swallowing disorder, which is a phenomenon where liquid enters into the trachea and penetrates the vocal fold, include H1-A1, H1-A2, B1, A1, A2, 2K (*)-5K and HNR (0-1500Hz).